DataDemo.json

[
    {
        "paper_title": "1,3,5\u2010Triphenylbenzene Based Porous Conjugated Polymers for Highly Efficient Photoreduction of Low\u2010Concentration CO<sub>2</sub> in the Gas\u2010Phase System",
        "paper_doi": "10.1002/solr.202100872", 
        "paragraphs": [
            {
                "paragraph_text": "Developing near-infrared responsive (NIR) photocatalysts is very important for the development of solardriven photocatalytic systems.Metal sulfide semiconductors have been extensively used as visible-light responsive photocatalysts for photocatalytic applications owing to their high chemical variety, narrow bandgap and suitable redox potentials, particularly the benchmark ZnIn 2 S 4 .However, their potential as NIR-responsive photocatalysts is yet to be reported.Herein, for the first time demonstrated that upconversion nanoparticles can be delicately coupled with hierarchical ZnIn 2 S 4 nanorods (UCNPs/ZIS) to assemble a NIR-responsive composite photocatalyst, and as such composite is verified by ultraviolet-visible diffuse reflectance spectra and upconversion luminescence spectra.As a result, remarkable photocatalytic CO and CH 4 production rates of 1500 and 220 nmol g A1 h A1 , respectively, were detected for the UCNPs/ZIS composite under NIR-light irradiation (k !800 nm), which is rarely reported in the literature.The remarkable photocatalytic activity of the UCNPs/ZIS composite can be understood not only because the heterojunction between UCNPs and ZIS can promote the charge separation efficiency, but also the intimate interaction of UCNPs with hierarchical ZIS nanorods can enhance the energy transfer.This finding may open a new avenue to develop more NIR-responsive photocatalysts for various solar energy conversion applications.",
                "annotations": [
                    {
                        "annotator": "hybrid annotation",
                        "category":"catalyst",
                        "value":"UCNPs/ZIS composite",
                        "context": "Herein, for the first time demonstrated that upconversion nanoparticles can be delicately coupled with hierarchical ZnIn₂S₄ nanorods (UCNPs/ZIS) to assemble a NIR-responsive composite photocatalyst"
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"light source",
                        "value":"Monochromatic",
                        "context": "NIR-light irradiation (k !800 nm)"
                    }
                ]

            },
            {
                "paragraph_text": "Indium nitrate (In(NO 3 ) 3 , 99.99), terephthalic acid (H 2 BDC, 99), rare earth chloride hexahydrate (YCl 3 A6H 2 O, YbCl 3 A6H 2 O, TmCl 3 A6H 2 O, 99.99), sodium hydroxide (NaOH, 96), ammonium fluoride (NH 4 F, 98), zinc chloride (ZnCl 2 , 99.99), oleic acid (OA, 99), 1-Octadecene (ODE, 99.5), cyclohexane (C 6 H 12 , 99.9), acetonitrile (CH 3 CN, 99.9), ethyl acetate (C 4 H 8 O 2 , 99.9), Triethanolamine (TEOA, 99) were purchased from Aladdin.Thiourea (CSNH 2 , 99 ), Ethanol (C 2 H 5 OH, 99.7), methanol (CH 3 -OH, 99.5) were purchased from Sinopharm Chemical reagent.All reagents were of analytical grade and used without further purification. The MIL-68(In) was synthesized by a modified previous report 39.Typically, 4.5 mg of In(NO 3 ) 3 and 5.5 mg of terephthalic acid (H 2 BDC) were dispersed in 2 mL of DMF solution, and the mixed solution was heated at 120 C for 30 min using an oil bath.Then, the white precipitation of MIL-68(In) was collected by centrifugation and washed with ethanol three times, and finally dried in a vacuum oven at 60 C. The ZIS nanorods were prepared by the solvothermal method.Typically, 20 mg of the above-prepared MIL-68(In) was dispersed in 30 mL of ethanol solution, and then (750 lL, 0.1 M) of ZnCl 2 solution and 200 mg of thiourea were added and stirred until the thiourea was fully dissolved.Then the resultant mixture was transferred into a Teflon-lined autoclave, tightly sealed and heated at 180 C for 3 h.After naturally cooling to room temperature, the product was collected by centrifugation and washed with ethanol three times.The final product was dried in a vacuum oven at 60 C. NaYF 4 : Yb, Tm coated with oleic acid were prepared through a high-temperature synthesis method.In a typical synthesis 40 , 0.795 mmol YCl 3 , 0.2 mmol YbCl 3 , 0.005 mmol TmCl 3 , 6 mL oleic acid, and 15 mL octadecene were added into a 50 mL threenecked flask.The mixture was stirred and heated at 160 C until it became a homogeneous solution.The solution was naturally cooled to room temperature, and then a methanol solution containing NaOH and NH 4 F was added dropwise and further stirred for 30 min.Following by evaporating the methanol and degassed at 100 C for 20 min.Then, the temperature was increased to 300 C in an argon atmosphere and kept for 1 h.After cooling to room temperature, the nanoparticles were deposited with absolute ethanol and washed 2-3 times with ethanol and cyclohexane.Finally, the product was dispersed in 10 mL cyclohexane for the subsequent experiments. In a typical process, 5 mg of the prepared ZIS powder and desired amount of UCNPs solution (200, 500, 1000, and 1500 lL) were mixed in ethyl acetate to make a total volume of 10 mL.The suspension was sonicated to homogeneity and then stirred at room temperature for 2 h.Finally, the precipitate was collected by centrifugation at 7000 rpm and dried in a vacuum at 60 C. Scanning electron microscope (SEM) and elemental mapping analysis were performed on Hitachi S-4800 SEM.Transmission electron microscope (TEM) and high-resolution TEM (HRTEM) analysis were performed on JEOL 2010F TEM.Powder X-ray diffraction (XRD) was tested on a Philips X' Pert Pro X-ray diffractometer equipped with Cu Ka rays.Ultraviolet-visible diffuse reflectance analysis (DRS) is performed on an Agilent-Cary 5000 spectrometer equipped with an integrating sphere.Electrochemical tests such as photocurrent and Mott Schottky (MAS) plot were carried out on the electrochemical workstation of CHI660D with a threeelectrode system using the Pt electrode as an auxiliary counter electrode, the Ag/AgCl electrode as a reference electrode, and the sample-coated FTO glass as the working electrode.The light source is a 300 W Xe lamp (PLS-SXE300) equipped with a NIR filter (k !800 nm), and 0.5 M Na 2 SO 4 solution is used as the electrolyte solution.X-ray photoelectron spectroscopy (XPS) is measured on an ESCALab MKII X-ray photoelectron spectrometer equipped with Mg-Ka X-rays.Steady-state fluorescence (PL) spectroscopy is tested using Hitachi H-4600 equipped with a 980 nm NIR laser (LR-MFI-980/1000 mW). The photocatalytic CO 2 reduction experiment was carried out in a 30 mL heat-resistant photoreactor.The light source is a 300 W Xe lamp (PLS-SXE300, Beijing Prefectlight, set at 100 mW cm A2) and the NIR light source is obtained by a 300 W Xe lamp equipped with an optical cut-off filter (k !800 nm).In a typical experiment, photocatalyst (5 mg) was suspended in acetonitrile (9 mL) with TEOA (1 mL) as an electron-donating agent.Before the photocatalytic reaction, the reaction cell was evacuated and refilled with highpurity CO 2 gas for 10 min.The photogenerated gas was detected by gas chromatography (GC, Agilent 7820A, Ar as carrier gas), and the concentration is corrected by the standard curve.",
                "annotations": [
                    {
                        "annotator": "hybrid annotation",
                        "category":"catalyst",
                        "value":"UCNPs/ZIS composite",
                        "context": "In a typical process, 5 mg of the prepared ZIS powder and desired amount of UCNPs solution [...] were mixed [...] to make a total volume of 10 mL."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"co_catalyst",
                        "value":"TEOA (Triethanolamine)",
                        "context": "photocatalyst (5 mg) was suspended in acetonitrile (9 mL) with TEOA (1 mL) as an electron-donating agent."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"light source",
                        "value":"Monochromatic",
                        "context": "photocatalyst (5 mg) was suspended in acetonitrile (9 mL) with TEOA (1 mL) as an electron-donating agent."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"lamp",
                        "value":"Xenon",
                        "context": "The light source is a 300 W Xe lamp (PLS-SXE300) [...] and the NIR light source is obtained by a 300 W Xe lamp"
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"reaction medium",
                        "value":"Liquid",
                        "context": "photocatalyst [...] was suspended in acetonitrile (9 mL) with TEOA (1 mL) [...]"
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"reactor type",
                        "value":"Slurry",
                        "context": "photocatalyst [...] was suspended in acetonitrile [...]"
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"operation mode",
                        "value":"Batch",
                        "context": "Before the photocatalytic reaction, the reaction cell was evacuated and refilled with high-purity CO₂ gas"
                    },
                    {
                        "annotator": "domain_expert_1",
                        "category":"light source",
                        "value":"",
                        "context": ""
                    },
                    {
                        "annotator": "domain_expert_1",
                        "category":"lamp",
                        "value":"",
                        "context": ""
                    }
                ]
            },
            {
                "paragraph_text": "TEM and SEM are applied to investigate the morphology of the as-synthesized UCNPs, MIL-68(In), ZIS, and UCNPs/ZIS samples.The TEM image in Fig. 1A reveals that the synthesized UCNPs is consist of regular hexagonal nanoparticles with an average particle size of 25 nm (Fig. S1).The SEM and TEM images of the MIL-68(In) precursor together with its XRD pattern (Fig. 1B and Fig. S2) display a pure phase of the MIL-68(In) and smooth nanorods with an average diameter of about 500 nm were observed.Interestingly, upon liquid phase sulfurization of the MIL-68(In) nanorods with Zn 2 solution, a hierarchical shell of the ZIS with a diameter of about 700 nm was obtained (Fig. 1C).The successful coupling of UCNPs with the hierarchical ZIS nanorods to form UCNPs/ZIS composite was also verified by TEM, which illustrates a good interface contact between small particles of the UCNPs (Green dotted circle) and the hierarchical ZIS nanorods (Fig. 1D).To further clarify the good interfacial interaction and gain more crystallographic information of the UCNPs/ZIS composites, the HRTEM of the UCNPs/ ZIS composites was examined.The HRTEM image in Fig. 1E implies an intimate interfacial interaction between the UCNPs and hierarchical ZIS nanorods crystallines with the lattice fringe space of 0.52 nm and 0.32 nm, corresponding to the (1 0 0) plane of UCNPs and the (1 0 2) plane of the ZIS, respectively 41,42.Besides, the element mapping analysis was carried out to confirm the composition and distribution of the elements in the UCNPs/ZIS.The result in Fig. 1F-N implies that the Zn, In, S, Na, Y, Yb, Tm, F elements are evenly distributed, which further confirms that there is good contact between the UCNPs and ZIS. The electronic chemical states and elements composition of the UCNPs/ZIS composite were characterized by XPS spectra.The full XPS survey spectra of the UCNPs/ZIS composite in Fig. S3 identified the presence of the Zn, In, S, Na, Y, Yb, Tm, F elements, which is following the EDX elemental mapping of the UCNPs/ZIS.To further expose the interaction between the UCNPs and hierarchical ZIS nanorods, the high-resolution XPS spectra of the UCNPs/ZIS composite were studied.The XPS spectrum of Zn 2p in Fig. 2A shows two characteristic peaks at 1021.3 eV and 1044.4 eV, corresponding to the binding energies of the Zn 2p 3/2 and 2p 1/2 , respectively 43.Compared with the XPS spectrum of the Zn 2p in the ZIS sample, we can notice that the two peaks of the XPS spectrum of Zn 2p are negatively shifted by 0.6 eV.A similar phenomenon of the negatively shifted binding energies of the In 3d 5/2 at 444.7 eV and In 3d 3/2 , at 452.2 eV for the XPS spectrum of In 3d by 0.6 eV was also observed (see Fig. 2B) 10,43, implying that the electron density near the Zn 2p and In 3d is increased.In contrast, the comparative high-resolution XPS spectrum analysis of the F and Yb in the UCNPs/ZIS (Fig. 2C andD) reveals that the binding energies of the F and Yb in UCNPs/ZIS are positively shifted by 0.1 eV, demonstrating that the electron density near the F 1 s and Yb 4d is decreased.The above XRD, SEM, TEM, HRTEM and XPS spectra of the synthesized UCNPs/ZIS integrally confirm the successful formation of the UCNPs/ZIS composite with the strong interfacial interaction between UCNPs and ZIS, benefiting the efficient energy transfer. Moreover, the XRD patterns were applied to investigate the phase purity of the synthesized ZIS, UCNPs, and UCNPs/ZIS samples.The results in Fig. 3A indicate that the synthesized hierarchical ZIS nanorods, UCNPs, and UCNPs/ZIS composite are pure phases without any impurities.All the peaks are well indexed to their corresponding standard card databases (PDF No. 65-2023 and PDF No. 16-0334) as illustrated together with their XRD patterns, signifying successfully prepared samples.The optical properties of the ZIS, UCNPs and UCNPs/ZIS samples were studied by DRS.The DRS result in Fig. 3B illustrates that the ZIS sample has an excellent visible light absorption edge at about 600 nm, corresponding to the bandgap of 2.08 eV estimated from Tauc plots (Fig. 3D).While UCNPs sample exhibits a full absorption range in the NIR region at 980 nm (Fig. 3C), indicating its capability of harvesting light in the NIR region.The DRS spectrum of the UCNPs/ZIS composite shows an analogous absorption characteristic to the ZIS with a narrow bandwidth in the NIR region at 980 nm (Fig. 3C), further demonstrating strong interfacial interaction between ZIS and UCNPs in the UCNPs/ZIS composite.Moreover, the electronic band was estimated to be ca.A0.74 V (vs.RHE) since the CB of n-type semiconductor photocatalyst is generally considered to be more negative ca. 0.2 V than the E fb 44,45.Consequently, its valence band (VB) was calculated to be ca.1.34 V (vs.RHE) by taking into account that the bandgap value of 2.08 eV.Accordingly, the estimated VB and CB positions of the ZIS are schematically drawn in Fig. 3F.Theoretically, for the ideal semiconductor photocatalysts to drive photocatalytic CO 2 /CO reduction reaction, it should have CB potentials located at more negative potential than that of the CO 2 /CO (uCO 2 /CO -0.12V, vs. RHE) 46.Hence, the CB of the ZIS is well straddling to the theoretical thermodynamic requirement for the photocatalytic CO 2 /CO reaction.Motivated by the unique optoelectronic properties of the ZIS, UCNPs and UCNPs/ZIS samples, a series of photocatalytic CO 2 reduction reactions were carried out to validate their potentials as photocatalysts.First, the photocatalytic CO 2 reduction reaction was conducted under the simulated solar light using acetonitrile as the solvent and the triethanolamine as an electrondonating reagent.The result in Fig. 4A indicates that no reduction product was detected for the pristine UCNPs sample, which might be due to the localization of electrons that can not be transferred to the surface of the semiconductor to initiate the catalytic reactions.Whilst CO and CH 4 with the production rates of 42.66 and 6.07 lmol g A1 h A1 , respectively, were detected for the pristine ZIS sample.Remarkably, the photocatalytic production rates of CO and CH 4 were significantly increased up to 52.84 and 8.55 lmol g A1 h A1 , respectively, when the UCNPs were delicately integrated with the hierarchical ZIS nanorods, indicat-ing the potential of ZIS and UCNPs/ZIS composite as efficient photocatalysts for photocatalytic CO 2 reduction.Additionally, the influence of the loading amount of the UCNPs in the UCNPs/ZIS sample on photocatalytic CO 2 production was also studied (Fig. S4A).The photocatalytic production rates reveal that the optimum amount of UCNPs in the UCNPs/ZIS sample is identified to be ca.500 lL, corresponding to the molar ratio of 2:1 (UCNPs: ZIS). It is worth mentioning here that controlling the reaction conditions and morphology plays a significant role in the physicochemical properties of the semiconductor photocatalysts 47,48, which greatly affects the performance of photocatalytic systems.To evaluate the merits of the hierarchical ZIS nanorods, bulk ZIS nanoparticles and ZIS nanosheets were also prepared.The morphologies and phase purities of the as-prepared samples are displayed in Fig. S5 (Detailed information of the preparation protocol is given in SI).Their corresponding photocatalytic productions are found to be lower than the hierarchical ZIS nanorods (Fig. 4B), implying that the superior photocatalytic activity of the hierarchical ZIS nanorods is presumably due to its unique hierarchical morphology, which provides more catalytic active sites and facilitates the charge separation and transfer.To gain insight into the merits of the ZIS with different morphologies, photocurrent measurement and EIS of bulk nanoparticles, nanosheets and hierarchical ZIS nanorods were carried out.The results exhibit that the ZIS with a hierarchical nanorods morphology shows a higher photocurrent response and smaller charge transfer resistance compared with nanosheets and bulk nanoparticles ZIS, respectively, implying that the ZIS with hierarchical nanorods can effectively boost the charge separation and transfer efficiencies (see Fig. S6). Moreover, to further confirm whether the developed UCNPs/ZIS acts as a photocatalyst in the given system, a series of control experiments were conducted under the same experimental condition.The result in Fig. S4B shows that when the entry is only CO 2 gas or UCNPs/ZIS under light irradiation; no gas was detected.A trace amount of CO gas was detected when Ar gas and UCNPs/ZIS were irradiated under simulated solar light, which might be due to the photocatalytic reduction of the small amount of CO 2 that is existing in the atmosphere.However, sound photocatalytic productions of CO and CH 4 were detected only when the entry is CO 2 gas and UCNPs/ZIS under simulated solar light irradiation, demonstrating that the UCNPs/ZIS is indeed an efficient photocatalyst.Furthermore, the photocatalytic stability test of the UCNPs/ZIS sample was also examined by re-evaluating its photocatalytic production activity for four consecutive reactions.The result in Fig. 4C indicates that no noticeable photocatalytic activity decay was witnessed, confirming that the proposed UCNPs/ZIS photocatalyst is stable under experimental conditions.To further elucidate the role of the UCNPs in the catalytic process, photocurrent measurements of the UCNPs/ZIS and ZIS samples were carried out.As shown in Fig. 4D, under the irradiation of simulated solar light the UCNPs/ ZIS composite exhibits a high photocurrent response than that of the ZIS sample, which is following the result of the photocatalytic CO 2 reduction (Fig. 4A).This result further suggested that the introduction of the optimum amount of UCNPs in UCNPs/ZIS can enhance the light absorption and increase the photogenerated carriers of the system. To prove the ability of the developed UCNPs/ZIS composite as a NIR-responsive photocatalyst, photocatalytic CO 2 reduction was examined under NIR-light irradiation (k !800 nm).The result in Fig. 5A shows that when the pristine UCNPs and ZIS were irradiated under the NIR-light no photocatalytic products were detected, which might be due to the insufficient light absorption of the ZIS in the NIR region and lack of reaction active site for the UCNPs.Interestingly, significant CO and CH 4 production rates of 1500 and 220 nmol g A1 h A1 , respectively, were detected for the UCNPs/ZIS composite under NIR-light irradiation (k !800 nm), demonstrating that the developed UCNPs/ZIS composite is indeed a NIRresponsive photocatalyst.The time-dependence in Fig. 5B confirm that the photocatalytic CO and CH 4 productions over the UCNPs/ZIS composite are steady-state increased with the increase of reaction time, and the recycling photocatalytic experiment for four consecutive runs in Fig. 5C highlighted that the UCNPs/ZIS composite has long-term photostability under photocatalytic reaction conditions.Besides, to evaluate the fate of the UCNPs/ZIS composite after the four cycles, the TEM and XRD pattern of the UCNPs/ZIS composite were also tested (see Fig. S7).The result shows that no morphology and crystal structure changes were observed, which further confirms the good stability of the developed UCNPs/ZIS composite.To further gain deep insight into the ability of the UCNPs/ZIS composite as a NIR-responsive photocatalyst, photocurrent tests of the UCNPs/ZIS and ZIS samples were also studied under NIR light irradiation.The result exhibits that no photocurrent response was detected for the pristine ZIS while a sound photocurrent response was detected for the UCNPs/ZIS composite (Fig. 5D), which is wellagreed with the photocatalytic CO 2 reduction result (see Fig. 5A), reflecting that the UCNPs/ZIS composite photocatalyst can effectively generate electrons and holes under the excitation of NIRlight irradiation.Hence, this result strongly certified the efficient energy transfer process between UCNPs and ZIS.Besides, the compared absorption spectrum of the ZIS with the emission spectrum of the UCNPs in Fig. 5E reveals that there is an overlap in a certain range, which is a prerequisite for the energy transfer.The photoluminescence spectra (PL) of the UCNPs and UCNPs/ZIS samples under an excitation wavelength of 980 nm were further examined (Fig. 5F).The PL intensity of the UCNPs/ZIS sample exhibits a significant quenching compared with the pristine UCNPs, which further reflects the existence of energy transfer from UCNPs to ZIS.The efficient energy transfer process of the system is one of the vital reasons for the high efficient photocatalytic performance of the UCNPs/ZIS composite.It is worth mentioning that, so far, this is the first study to demonstrate that the UCNPs/ZIS composite can function as an efficient NIR-responsive photocatalyst for photocatalytic CO 2 reduction.It is essentially important to understand the possible photocatalytic reaction mechanism involved in the UCNPs/ZIS composite.Upon NIR-light irradiation at 980 nm, UCNPs can absorb NIR light and then emit UV or visible light via an anti-stokes shift luminescence process.Typically, as schematically elucidated in scheme 2, during the excitation processes, first the sensitizer ions Yb 3 will be excited from the ground state ( 2 F 7/2 ) to the metastable state ( 2 F 5/2 ).Consequently, Tm 3 will be exited from the ground state to the different excited states (( 3 H 6 ? 3 H 5 ), ( 3 H 5 ? 3 F 2 ), ( 3 H 4 ? 1 G 4 ), ( 3 H 4 ? 1 D 2 ) and ( 1 D 2 ? 3 P 2 )) due to continuous energy transfer from the sensitizer Yb 3 ions 27, and emits higher-energy photons (UV and visible light), such as 347 nm ( 1 I 6 ? 3 F 4 ), 362 nm ( 1 D 2 ? 3 H 6 ), 452 nm ( 1 D 2 ? 3 F 4 ), and 476 nm ( 1 G 4 ? 3H 6 ).Then, the upconverted UV and visible emissions from Tm 3 will be absorbed by the ZIS and generate electrons and holes.The efficient energy transfer between the UCNPs and ZIS resulted in significant photocatalytic reduction of CO 2 to CO and CH 4 productions under NIR-light irradiation.",
                "annotations": [
                    {
                        "annotator": "hybrid annotation",
                        "category":"catalyst",
                        "value":"UCNPs/ZIS composite",
                        "context": "Remarkably, the photocatalytic production rates of CO and CH₄ were significantly increased [...] when the UCNPs were delicately integrated with the hierarchical ZIS nanorods, indicating the potential of [...] UCNPs/ZIS composite as efficient photocatalysts."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"co_catalyst",
                        "value":"TEOA (Triethanolamine)",
                        "context": "The photocatalytic CO₂ reduction reaction was conducted [...] using acetonitrile as the solvent and triethanolamine as an electron-donating reagent."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"light source",
                        "value":"Solar Simulator, Monochromatic ",
                        "context": ["The photocatalytic CO₂ reduction reaction was conducted under the simulated solar light [...].", "Photocatalytic CO₂ reduction was examined under NIR-light irradiation (λ ≥800 nm)."]
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"lamp",
                        "value":"Xenon",
                        "context": "The light source is a 300 W Xe lamp [...] equipped with a NIR filter (λ ≥800 nm)."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"reaction medium",
                        "value":"Liquid",
                        "context": "Photocatalyst [...] was suspended in acetonitrile (9 mL) with TEOA (1 mL) [...]."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"reactor type",
                        "value":"Slurry",
                        "context": "photocatalyst [...] was suspended in acetonitrile [...]"
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"operation mode",
                        "value":"Batch",
                        "context": "Before the photocatalytic reaction, the reaction cell was evacuated and refilled with high-purity CO₂ gas [...]."
                    }
                ]
            },
            {
                "paragraph_text": "In summary, a high efficient NIR-driven photocatalytic CO 2 reduction system based on delicately coupled UCNPs with the hierarchical ZIS nanorods (UCNPs/ZIS) was demonstrated.The assembled UCNPs/ZIS composite can function as a NIR-responsive photocatalyst as confirmed by ultraviolet-visible diffuse reflectance spectra and upconversion luminescence spectra.As a proof of concept, remarkable photocatalytic productions of CO and CH 4 were detected under NIR-light irradiation (k !800 nm) with high stability, demonstrating that the developed UCNPs/ZIS composite is an efficient and stable NIR-responsive composite photocatalyst.The improvement of the photocatalytic performance of the developed UCNPs/ZIS composite is due to the unique hierarchical morphology, which facilitates the interaction between ZIS nanorods and small particles of the UCNPs as well as provides abundant catalytic active sites for photocatalytic CO 2 reduction.Additionally, the intimate contact between the UCNPs and hierarchical ZIS nanorods can also promote charge separation efficiency and energy transfer.This finding may offer a new vision into the rational development of more NIR-responsive photocatalysts. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Scheme 1. Schematic illustration of the synthetic process of the UCNPs/ZIS composite. Fig. 1. (A) TEM image of UCNPs.(B) SEM image of MIL-68(In) precursor.(C) SEM image of ZIS nanorods.(D) TEM image of UCNPs/ZIS.(E) HRTEM of the UCNPs/ZIS.(F-N) SEM elemental mapping of UCNPs/ZIS. Fig. 2. (A-D) High-resolution XPS spectrum of the Zn 2p, In 3d, F 1 s, and Yb 4d in the ZIS and UCNPs samples compared with the UCNPs/ZIS sample. Fig. 4. Simulated solar light irradiation driven (A and B) CO and CH 4 productions over different photocatalysts and ZIS with the different morphologies, (C) Photocatalytic stability tests of UCNPs/ZIS, and (D) Photocurrent response of the UCNPs/ZIS and ZIS samples. Fig. 5. NIR-light irradiation driven (A) Cases production, (B) Time-dependent Cases production of UCNPs/ZIS, (C) Photocatalytic stability tests of UCNPs/ZIS, and (D) Photocurrent test of the UCNPs/ZIS and ZIS.(E) Absorption and emission spectral overlap of ZIS and UCNPs.(F) PL spectra of the UCNPs and UCNPs/ZIS (kex 980 nm). Mengshi Yu: Experimented and analyzed the data.. Xiaoyu Lv: Experimented and analyzed the data.. Ahmed Mahmoud Idris: supervised the project and wrote the original draft together with Mengshi Yu.Suhang Li: Investigation.Jiaqi Lin: Investigation.Heng Lin: Investigation.Jin Wang: Software, Supervision.Zhengquan Li: Conceptualization, Writing -review editing. M. Yu, X. Lv, A. Mahmoud Idris et al.Journal of Colloid and Interface Science 612 (2022) 782-791 This work was financially supported by the National Natural Science Foundation of China (21975223, 21701143) and the Zhejiang Province Public Welfare Technology Application Research Project (LGG19B010002). Supplementary data to this article can be found online at https://doi.org/10.1016/j.jcis.2021.12.197.",
                "annotations": [
                    {
                        "annotator": "hybrid annotation",
                        "category":"catalyst",
                        "value":"UCNPs/ZIS composite",
                        "context": "In summary, a high efficient NIR-driven photocatalytic CO₂ reduction system based on delicately coupled UCNPs with the hierarchical ZIS nanorods (UCNPs/ZIS) was demonstrated."
                    },
                    {
                        "annotator": "hybrid annotation",
                        "category":"light source",
                        "value":"Solar Simulator, Monochromatic ",
                        "context": ["Simulated solar light irradiation driven [...] CO and CH₄ productions over different photocatalysts [...].", "Remarkable photocatalytic productions of CO and CH₄ were detected under NIR-light irradiation (λ ≥800 nm)."]
                    }
                ]
            }
        ]
    }
]