Photocatalytic CO2 Reduction Performance Research Articles

Tree-inspired semiconductor-on-ceramic 2D/1D heterostructure for efficient CO2 photoreduction

Two-dimension nanosheets are ideal photocatalysts for CO2 reduction due to their high exposure of active sites and short charge transfer pathway. However, 2D photocatalysts have a tendency to agglomeration, thus compromising the performance of photocatalytic CO2 reduction. Trees, one of the most important plants for photosynthesis, have a unique “leaf-on-branch” structure. This unique two-dimension/one-dimension (2D/1D) configuration maximizes the adsorption of CO2 molecules and light harvesting. Herein, a tree-inspired semiconductor-on-ceramic 2D/1D heterostructure for efficient photocatalytic CO2 reduction is reported. The cobalt silicate (CoSi) nanosheets (∼0.68 nm) are in situ grown on the surfaces of hydroxyapatite (HAP) nanowires, creating a well-defined 2D/1D hierarchical structure. The vertical alignment of ultrathin CoSi nanosheets on the HAP nanowires effectively suppresses their agglomeration, leading to a large BET surface area (106.45 m2/g) and excellent CO2 adsorption (8.00 cm3 g−1). The results of photoelectrochemical characterization demonstrate that the 2D/1D hierarchical structure is powerful to expedite charge transfer. As a result, the gas generation rate of CO is as high as 28780 μmol g−1 h−1 over the CoSi-on-HAP 2D/1D heterostructure. In addition, the electron transfer mechanism and reaction pathways of CO2 reduction are revealed by in situ irradiated XPS and in situ DRIFT spectra.

Nanoengineering construction of g-C3N4/Bi2WO6 S-scheme heterojunctions for cooperative enhanced photocatalytic CO2 reduction and pollutant degradation

S-scheme heterojunction photocatalysts featuring efficient charge transport paths provide a promising strategy for cooperative achieving photocatalytic CO2 reduction reaction (CO2RR) and Rhodamine B (RhB) degradation. In this work, S-scheme heterojunctions composed of g-C3N4 nanosheets coated on Bi2WO6 nanosheets were prepared by a one-step hydrothermal method, resulting in broad-spectrum light absorption, high electron–hole separation efficiency, and excellent photocatalytic CO2 reduction and RhB oxidization performance. Mechanistic analysis revealed the formation of a directional charge transport path at the interface of the heterojunction, which maintained a high oxidation and reduction potential and improved the efficiency of photoexcited carrier separation. In particular, the synergistic reaction system showed excellent photoredox activity compared with the two separate half-reactions. The optimal catalyst 15CN/BWO displayed the highest CO2 conversion efficiency, with CO and CH4 generation rates of 4.3 and 2.7 μmol g−1h−1, respectively, and the degradation efficiency of the composite heterojunction was significantly higher than that of its constituent materials. This work provides a new possibility for designing a novel dual-function photocatalytic reaction system.

Synergetic regulation of interfacial electronic structure of Cu, N co-doped carbon modified TiO2 for efficient photocatalytic CO2 reduction

TiO2 was a promising candidate material for CO2 photoreduction, but its development was greatly limited due to inherent defects such as high recombination rate of photogenerated charge carriers and limited number of active sites. In this study, a method involving chelation of metal ions with amino acids followed by high-temperature pyrolysis was employed to prepare Cu, N co-doped carbon-modified TiO2 composite materials, aiming to enhance the photocatalytic CO2 reduction performance of TiO2. The introduction of Cu, N co-doped carbon effectively improved the surface morphology of TiO2, increased the specific surface area and porosity, and enhanced the adsorption capacity of CO2. Simultaneously, the modification of TiO2 by Cu, N co-doped carbon optimized the electronic structure of catalysts, facilitating the separation and transfer of photogenerated electron-hole pairs, reducing charge carrier recombination, and thereby synergistically improving the thermodynamics and kinetics of CO2 reduction. Photocatalytic performance tests revealed that 10 % Cu-TiO2 exhibited the best CO2 reduction performance at a calcination temperature of 450 °C, with a CO production rate of up to 46 μmol·g−1·h−1, approximately 18 times that of pure TiO2. Density functional theory (DFT) calculations further confirmed that the introduction of Cu, N co-doped carbon reduced the Gibbs free energy of the CO2 reduction reaction, promoting the reaction. This study provides a simple, cost-effective strategy for developing efficient photocatalytic CO2 reduction materials.

Identification of intrinsic vacancies and polarization effect on ternary halo‐sulfur‐bismuth compounds for efficient CO2 photoreduction under near‐infrared light irradiation

AbstractTernary halo‐sulfur bismuth compound Bi19X3S27 (X = Cl, Br, I) with distinct electronic structure and full‐spectrum light‐harvesting properties show great application potential in the CO2 photoreduction field. However, the relationship between photocatalytic CO2 reduction performance and the function of halogens in Bi19X3S27 is still poorly understood. Herein, a series of Bi19X3S27 nanorod photocatalysts with intrinsic X and S dual vacancies were developed, which showed significant near‐infrared (NIR) light responses. The types and concentrations of intrinsic vacancies were confirmed and quantified by positron annihilation spectrometry and electron spin resonance spectroscopy. Experimental results showed that Br atoms and intrinsic vacancies (dual Br‐S) in Bi19Br3S27 could greatly enhance the internal polarized electric field and improve the transfer and separation of photogenerated carriers compared with Bi19Cl3S27 and Bi19I3S27. Theoretical calculations revealed that Br atoms in Bi19Br3S27 could facilitate CO2 adsorption and activation and decrease the formation energy of reactive hydrogen. Among Bi19X3S27 nanorods, Bi19Br3S27 nanorods revealed the highest CO2 photoreduction activity with CO yield rate of 28.68 and 2.28 μmol gcatalyst−1 h−1 with full‐spectrum and NIR lights, respectively. This work presents an atomic understanding of the intrinsic vacancies and halogen‐mediated CO2 photoreduction mechanism.

MOFs-derived S-scheme ZnO/BiOBr heterojunction with rich oxygen vacancy for boosting photocatalytic CO2 reduction

In this paper, a MOFs-derived S-scheme ZnO/BiOBr heterojunction photocatalyst was constructed by a one-step calcination method. It was found that the dodecahedral ZnO was well attached to the BiOBr hollow rods in ZnO/BiOBr composites, which could simultaneously introduce oxygen vacancies and enhance interfacial interactions. The photocatalytic CO2 reduction results exhibited that ZnO/BiOBr, without adding any sacrificial agent and photosensitiser, produced CO and CH4 at rates of 21.13 μmol·g−1·h−1 and 2.2 μmol·g−1·h−1 under simulated sunlight, with a CO selectivity of 74.34 %, which was 6.35 and 4.07 times higher than that of the original BiOBr as well as the original ZnO 4.14 and 1.98 times, respectively. The optimised ZnO/BiOBr has excellent photocatalytic CO2 reduction performance. The ZnO/BiOBr photocatalyst has excellent stability after 5 cycles. The unique heterostructures and matched energy band potentials between ZnO and BiOBr provided close interfacial contacts, a large number of active sites and effective charge transferred for photocatalytic CO2 reduction. Furthermore, the mechanism of photocatalytic CO2 reduction for S-scheme ZnO/BiOBr heterojunction was also proposed. Therefore, the MOFs-derived ZnO/BiOBr composites had the potential to be used as photocatalyst for CO2 reduction, providing a rational design idea for solar energy-driven CO2 conversion of MOFs-structured photocatalysts.

ZIF-8/g-C3N4 photocatalysts: enhancing CO2 reduction through improved adsorption and photocatalytic performance.

Nowadays, the widespread concern over controlling CO2 emissions and mitigating the adverse effects of greenhouse gases on global climate has attracted significant attention. In this study, g-C3N4 was synthesized by thermopolymerizing urea. Subsequently, ZIF-8 was combined with g-C3N4 using an in situ deposition method, resulting in the fabrication of ZIF-8/g-C3N4 composite photocatalysts at various molar ratios. Effective incorporation of ZIF-8 into g-C3N4 suppressed the recombination of photogenerated electrons and holes, thereby enhancing CO2 capture capacity and preserving light absorption capabilities. The ZIF-8/g-C3N4 composite demonstrates excellent photocatalytic performance for CO2 reduction, where the optimized material exhibited a CO2 adsorption capacity 1.52 times that of pure g-C3N4 and increased the conversion of CO2 to CH4 by more than sevenfold. This study harnesses the superior CO2 adsorption properties of metal-organic frameworks to develop more efficient photocatalysts, enhancing CO2 conversion efficacy and offering insights for developing efficient photocatalysts that utilize CO2.

Multi-Variable Multi-Metric Optimization of Self-Assembled Photocatalytic CO2 Reduction Performance Using Machine Learning Algorithms.

The sunlight-driven reduction of CO2 into fuels and platform chemicals is a promising approach to enable a circular economy. However, established optimization approaches are poorly suited to multivariable multimetric photocatalytic systems because they aim to optimize one performance metric while sacrificing the others and thereby limit overall system performance. Herein, we address this multimetric challenge by defining a metric for holistic system performance that takes multiple figures of merit into account, and employ a machine learning algorithm to efficiently guide our experiments through the large parameter matrix to make holistic optimization accessible for human experimentalists. As a test platform, we employ a five-component system that self-assembles into photocatalytic micelles for CO2-to-CO reduction, which we experimentally optimized to simultaneously improve yield, quantum yield, turnover number, and frequency while maintaining high selectivity. Leveraging the data set with machine learning algorithms allows quantification of each parameter's effect on overall system performance. The buffer concentration is unexpectedly revealed as the dominating parameter for optimal photocatalytic activity, and is nearly four times more important than the catalyst concentration. The expanded use and standardization of this methodology to define and optimize holistic performance will accelerate progress in different areas of catalysis by providing unprecedented insights into performance bottlenecks, enhancing comparability, and taking results beyond comparison of subjective figures of merit.

In Situ Etching-Hydrolysis Strategy To Construct an In-Plane ZnIn2S4/In(OH)3 Heterojunction with Enhanced CO2 Photoreduction Performance.

The in-plane heterojunctions with atomic-level thickness and chemical-bond-connected tight interfaces possess high carrier separation efficiency and fully exposed surface active sites, thus exhibiting exceptional photocatalytic performance. However, the construction of in-plane heterojunctions remains a significant challenge. Herein, we prepared an in-plane ZnIn2S4/In(OH)3 heterojunction (ZISOH) by partial conversion of ZnIn2S4 to In(OH)3 through the addition of H2O2. This in situ oxidation etching-hydrolysis approach enables the ZISOH heterojunction to not only preserve the original nanosheet morphology of ZnIn2S4 but also form an intimate interface. Moreover, generated In(OH)3 serves as an electron-accepting platform and also promotes the adsorption of CO2. As a result, the heterojunction exhibits a remarkably enhanced performance for photocatalytic CO2 reduction. The production rate and selectivity of CO reach 1760 μmol g-1 h-1 and 78%, respectively, significantly higher than those of ZnIn2S4 (842 μmol g-1 h-1 and 65%). This work puts forward a feasible and facile approach to construct in-plane heterojunctions to enhance the photocatalytic performance of two-dimensional metal sulfides.

Interlayer anions modulated ZnAl-layered double hydroxides for enhanced photocatalytic CO2 reduction

Photocatalytic CO2 reduction has drawn widespread attention across all sectors of society. Layered double hydroxides (LDHs) have emerged as promising photocatalysts, renowned for their adjustable bandgaps and reaction sites. As a typical anionic layered material, LDHs exhibit intricate interactions between interlayer anions and brucite-like metal layers, greatly influencing their inherent physicochemical properties. In this work, we synthesized ZnAl-LDH samples intercalated with four distinct anions: carbonate (CO32–), chloridion (Cl–), nitrate (NO3–), and dodecyl sulfate (DS–), denoted as LDH-CO3, LDH-Cl, LDH-NO3, and LDH-DS, respectively. These LDHs samples have comparable crystallinity and morphology but differ in their interlayer spacing. XRD results reveal interlayer spacings of 0.77 nm for LDH-CO3, 0.78 nm for LDH-Cl, 0.88 nm for LDH-NO3, and 1.24 nm for LDH-DS, between adjacent brucite-like ZnAl hydroxide layers. Remarkably, LDH-NO3 demonstrates the highest photocatalytic CO2 reduction performance, with CO as the primary reduction product. Specifically, the average CO production rate of LDH-NO3 are 3.80 μmol g–1 h–1, surpassing that of LDH-CO3, LDH-Cl, and LDH-DS by 1.9, 2.1, and 2.5 times, respectively. This superior performance can be attributed to the intermediate interlayer spacing of LDH-NO3, which facilitates strong light absorption and a robust local built-in electric field. Theses properties enhance charge generation and separation abilities, leading to efficient photocatalytic reactions. The obtained results highlight the critical role of controlling small molecules within the interlayer, alongside defects, in the design and fabrication of layered-structure photocatalysts. This study provides valuable insights into optimizing the performance of LDH-based photocatalysts for CO2 reduction and potentially other photocatalytic applications.

Insights into the effect of Ni doping on In2S3 for enhanced activity and selectivity of photocatalytic CO2 reduction

The limited photocatalytic CO2 reduction performance mainly lies in the low utilization of photogenerated electrons during the reaction. In this work, we developed the defect level within the Ni-doped In2S3 nanotube photocatalysts via a simple solvothermal method to increase the available amount of photogenerated electrons for enhanced photocatalytic CO2 reduction performance than the pristine In2S3. The introduction of Ni element into the lattice of In2S3 could significantly improve the photocatalytic activity and selectivity without destruction of the nanotube structure of In2S3. The yield of CO reaches 243.2 μmol/g/h under visible light, which is the highest reported value among In2S3 photocatalysts, and is 8.2 times more than the pure In2S3. Moreover, by modulating the doping amount of Ni element, the selectivity of CO varied from 27.7% to 51.0%. Further characterizations suggest that the doping of Ni element altered the electronic bandgap arrangement of In2S3, where the position of the conduction band is conducive to the activation of CO2 molecules. Moreover, the defect level resulting from Ni-doping not only facilitates the separation of photoexcited electron-hole pairs but also suppresses the recombination of electrons and holes. This study provides an available and reliable strategy for enhancing the photocatalytic CO2 reduction performance of related sulfide photocatalytic materials in future studies.

2D/1D nested hollow porous ZnIn2S4/g-C3N4 heterojunction based on morphology modulation for photocatalytic CO2 reduction

The two-dimensional (2D) composite one-dimensional (1D) heterojunction structure is one of the main strategies for constructing composite photocatalysts for photocatalytic reduction of carbon dioxide (CO2). However, morphology modulation for 2D/1D heterojunction is an important way to enhance performance. In this study, a unique 2D/1D ZnIn2S4/g-C3N4 nested hollow porous heterojunction structure was constructed by an in-situ growth method with spatial confinement effect. The synergy between 1D g-C3N4 and 2D ZnIn2S4, achieved through advanced morphology modulation at an optimal ratio of 3:1, results in the formation of the CZ-3 photocatalyst. This unique configuration enables a simultaneous high yield of carbon monoxide (CO) and methane (CH4), achieving 79.96 μmol/g and 17.33 μmol/g respectively, under visible light irradiation without the need for sacrificial agents. The core of this enhanced photocatalytic performance is attributed to the employment of a type-II heterojunction mechanism, which optimizes the transfer of photogenerated carriers. Ultraviolet-visible diffuse reflection spectrum, photoluminescence spectrum and photoelectrochemical analysis reveal the effect of morphology on photocatalytic performance in terms of visible light absorption, photogenerated carrier pairs separation and electronic band structure of heterojunction. By combining the advantages of 2D/1D structural benefits with the efficient charge dynamics of a type-II heterojunction, this work provides new ideas for improving the morphology of composite heterojunction photocatalysts with 2D/1D structure to enhance the photocatalytic CO2 reduction performance.

Advances in Defect Engineering of Metal Oxides for Photocatalytic CO2 Reduction.

Photocatalytic CO2 reduction technology, capable of converting low-density solar energy into high-density chemical energy, stands as a promising approach to alleviate the energy crisis and achieve carbon neutrality. Semiconductor metal oxides, characterized by their abundant reserves, good stability, and easily tunable structures, have found extensive applications in the field of photocatalysis. However, the wide bandgap inherent in metal oxides contributes to their poor efficiency in photocatalytic CO2 reduction. Defect engineering presents an effective strategy to address these challenges. This paper reviews the research progress in defect engineering to enhance the photocatalytic CO2 reduction performance of metal oxides, summarizing defect classifications, preparation methods, and characterization techniques. The focus is on defect engineering, represented by vacancies and doping, for improving the performance of metal oxide photocatalysts. This includes advancements in expanding the photoresponse range, enhancing photogenerated charge separation, and promoting CO2 molecule activation. Finally, the paper provides a summary of the current issues and challenges faced by defect engineering, along with a prospective outlook on the future development of photocatalytic CO2 reduction technology.

Facile synthesis of MOF–808/RGO-based 3D macroscopic aerogel for enhanced photoreduction CO2

Three-dimensional (3D) macroscopic aerogels have emerged as a critical component in the realm of photocatalysis. Maximizing the integration of materials can result in enhanced efficiency and selectivity in photocatalytic processes. In this investigation, we fabricated MOF-808/reduced graphene oxide (RGO) 3D macroscopic aerogel composite materials employing the techniques of hydrothermal synthesis and freeze-drying. The results revealed that the macroscopic aerogel material exhibited the highest performance in CO2 reduction to CO, particularly when the concentration of RGO was maintained at 5 mg mL−1. In addition, we synthesized powder materials of MR-5 composite photocatalysts and conducted a comparative analysis in terms of photocatalytic CO2 reduction performance and electron transfer efficiency. The results showthat the macroscopic aerogel material boasts a high specific surface area, an abundant internal pore structure, and increased active sites. These attributes collectively enhance light energy utilization, and electron transfer rates, thereby, improving photothermal and photoelectric conversion efficiencies. Furthermore, we conducted in-situ FT-IR measurements and found that the M/R-5 aerogel exhibited the best CO2 adsorption capacity under a CO2 flow rate of 10 mL min−1. The density functional theory results demonstrate the correlation between the formation pathway of the product and the charge transfer pathway. This study provides useful ideas for realizing photocatalytic CO2 reduction of macroscopic aerogel materials in gas–solid reaction mode.

Hydrothermal synthesis of Ce-doped SnS2 2D nanoplates with enhanced photocatalytic CO2 reduction performance

CO2 emissions caused by human activities seriously influence the climate of earth and hinder the sustainable development of humans and nature. Photocatalytic CO2 reduction is an effective method to convert CO2 into other chemicals and reduce CO2 emissions. Here, Ce doped SnS2 photocatalyst has been obtained by using a hydrothermal method. The phase and structure of obtained samples have been characterized and the photocatalytic CO2 reduction performance has been evaluated. The results show that Ce dopants can improve visible light absorption, increase the specific surface area, especially increase the adsorption of CO2. The influence of Ce doping concentration was investigated to optimize the photocatalytic performance. Compared to the pristine SnS2 photocatalyst, the Ce–SnS2 reached 46.9 μmol g−1 h−1 in the CO2 photo-reduced test, which is 3.21 times that of pristine SnS2 photocatalyst. The enhanced photocatalytic performance can be attributed to Ce dopant which increases the specific surface and CO2 absorption quantity, and reduces the recombination of photogenerated electrons and holes.

Insights into bimetallic single-atom-doped g-C3N4 photo-catalysts for CO2 conversion to HCOOH: A DFT study

Developing low-cost, high-efficiency non-noble metallic photocatalytic materials is crucial for CO2 reduction. This paper investigates the substitution of noble metals dopant to a bimetallic non-noble Fe/Co dopant for g-C3N4 to enhance the photocatalytic CO2 reduction performance via density functional theory (DFT) calculations. This study examines the structure, electronic properties, CO2 adsorption configurations, and the transition states and Gibbs free energy of CO2 reduction to HCOOH on noble metal Pt/g-C3N4 doped, single-atom Fe/g-C3N4 doped, and bimetallic Fe/Co doped g-C3N4 catalysts, revealing the mechanisms of catalyst-mediated CO2 reduction. The results demonstrate that the introduction of Fe/Co bimetallic atoms leads to more efficient charge transfer, attributed to the synergistic and electronic effects of the bimetallic coupling, with a charge of 1.264, which is 2.2 and 1.2 times greater than that of Pt and Fe doped g-C3N4, respectively. Furthermore, the stronger adsorption energy of CO2 molecules on Fe/Co/g-C3N4 compared to pure g-C3N4, Pt/g-C3N4, and Fe/g-C3N4 indicates that adsorption on Fe/Co/g-C3N4 is more conducive to CO2 activation. The CO2 reduction reaction (CO2RR) calculations reveal that Fe/Co/g-C3N4 exhibits a lower reaction barrier of 0.789 eV compared to noble metal-doped Pt and single-atom Fe, due to the reduction of the reaction mechanism's energy barrier by the Fe/Co bimetallic doped g-C3N4, which facilitates a more effective reduction of CO2 to HCOOH. As a result, Fe/Co/g-C3N4 emerges as an effective alternative to noble metal-based photocatalysts. This study provides theoretical guidance for the preparation of efficient non-noble metal photocatalysts.

Engineering ZIF-67 loaded nanofibrous membrane with thermal stabilization treatment for efficient photocatalytic CO2 reduction

The photocatalytic Metal-organic frameworks (MOFs) membrane addresses challenges faced by MOF powders in practical applications such as aggregation and difficult recovery, but its current application is mainly confined to wastewater treatment. Expanding the application of MOFs membranes to CO2 reduction could unleash their greater potential in energy conversion and storage field. In this study, ZIF-67 was deposited on polyacrylonitrile (PAN) nanofiber membranes (NFMs) using an in-situ growth technique, followed by thermal stabilization to produce SZIF-67/PAN NFMs for photocatalytic CO2 reduction. ZIF-67 was uniformly and densely distributed on the NFMs, with a mass loading of up to 8 wt%. The thermal stabilization process significantly enhanced the photothermal conversion capability and solvent resistance of the NFMs, enabling SZIF-67/PAN NFMs to exhibit outstanding photocatalytic activity even under mild environmental conditions, with a remarkable CO generation rate of 39,250 μmol g−1h−1. Furthermore, the performance remained at 70 % even after five consecutive tests. This study presents a novel and effective method for preparing MOF NFMs with excellent photocatalytic CO2 reduction performance, offering valuable insights for advancing the practical application of MOF materials.

Ligand-engineered Cu-based halide perovskite for highly efficient near-infrared photocatalytic CO2 reduction

A key challenge in harvesting solar energy for efficient chemical conversion is the lack of photocatalysts with wide activation wavelengths. Herein, we propose for the first time to utilize halide perovskite to absorb the full spectrum (200–2500 nm), including ultraviolet (UV), visible (Vis), and near-infrared (NIR) light, to directly power photocatalytic CO2 reduction. This full-spectrum light-responsive occurs on metal halide perovskite Cs2CuCl4 microcrystals (MCs), and the ligand soybean lecithin is applied to optimize the active phase of Cs2CuCl4 photocatalyst, such as morphology, particle size, crystal face and electronic structure. As revealed by optical absorption analysis, the Cs2CuCl4 and ligand soybean lecithin modified Cs2CuCl4 (SL-Cs2CuCl4) MCs exhibit significant optical absorption in the UV, Vis light and NIR light regions. The photocatalytic CO2 reduction performance was assessed under simulated sunlight (200–2500 nm), and the SL-Cs2CuCl4 MCs achieved a CO fuel yield of 254.46 µmol g−1, which increased the yield by 5 times relative to the initial sample. Based on in-situ Fourier transform infrared, electron spin resonance and X-ray photoelectron spectroscopy, the active substances and reaction intermediates at the active site of SL-Cs2CuCl4 MCs were dynamically monitored, and the photocatalytic mechanism was revealed together with density functional theory (DFT) calculations. The DFT calculation shows that the photocatalytic reduction of CO2 to CO by Cs2CuCl4 is proposed to involve the concerted action of both Cs and Cu sites.

BiOCl/BiOBr composites for efficient photocatalytic carbon dioxide reduction

BiOBr (BOB) photocatalysts have low photocatalytic CO2 reduction performance due to their low electron-hole pair separation efficiency. To improve this problem, BiOCl (BOCl) is used as a co-catalyst. BOCl is loaded into BOB to form BiOCl/BiOBr (BOCl/BOB) type Ⅰ heterojunction, which enhances the photocatalytic CO2 reduction performance of BOB by promoting the separation of photogenerated electrons and holes. The results of TPR and PL experiments show that the 20% BOCl/BOB composites have the highest photogenerated carrier separation rate, and the results of CO2 reduction experiments show that 20% BOCl/BOB composites have the best photocatalytic CO2 reduction performance of 7.353 μmolg−1h−1, which is 3.22 and 1.99 times higher than pure BOB and BOCl, respectively. This work provides an effective reference for the development of modified photocatalysts.

Construction of carbonized polymer dots/potassium doped carbon nitride nanosheets Van der Waals heterojunction by ball milling method for facilitating photocatalytic CO2 reduction performance in pure water

When the advancement of conventional heterojunctions is restricted by lattice matching of materials, Van der Waals heterojunctions formed by interlayer Van der Waals force present enormous development prospects with the revolution of graphene and graphene-like materials. Ascribed to similar graphene-like structures, carbonized polymer dots (CPDs) and potassium-doped carbon nitride nanosheets (KCNNS) were stacked by the ball milling method to form a novel Van der Waals heterojunction. Experimental analysis and density functional theory (DFT) calculations demonstrate that the constructed CPDs/KCNNS heterojunctions can effectively suppress sluggish reaction dynamics. CPDs/KCNNS-2 composites demonstrate enhanced CO2 photoreduction performance (78.98 μmol g−1∙h−1) with 100% CO selectivity in pure water, which is 13.71 times higher than that of KCNNS. In-situ FT-IR spectra were employed to identify the intermediates formed in the CO evolution process of CPDs/KCNNS composites. The manuscript provides a scientific reference for the stacking of Van der Waals heterojunction based on C3N4 in the artificial photosynthesis field.

Effect of substrate and oxygen-argon ratio on photocatalytic CO2 reduction in ITO films prepared by magnetron sputtering

The internal electron transport capacity of the semiconductor directly affects whether there is a sufficient number of photogenerated electrons involved in the catalytic reaction process, thus determining the photocatalytic efficiency. Indium tin oxide (ITO), as an excellent conductive material, has convenient internal electron transport and can be used as a good photocatalyst directly. In this paper, ITO films on three different conductive substrates were prepared by DC sputtering method, and the crystallization and appearance of each sample were compared. Different substrates affect the energy band position of catalyst. The performance of photocatalytic CO2 reduction was tested. We found that ITO films grown on carbon cloth (CC) substrate have good photocatalytic properties. The atmosphere ratio in the preparation process also has a certain influence on the performance of the sample. Compared with ITO conductive glass widely used in the market, our improved ITO film has better photocatalytic properties and practicability. This work provides a certain reference for the application of ITO in the field of photocatalysis.