In-situ construction of amorphous/crystalline contact Bi2S3/Bi4O7 heterostructures for enhanced visible-light photocatalysis

Constructing a heterojunction photocatalyst is a significant method to enhance photocatalytic activity because it can promote the separation of photogenerated carriers. Herein, amorphous/crystalline contact Bi₂S₃/Bi₄O₇ heterostructure was successfully synthesized by in-situ sulfidation of Bi₄O₇. The amorphous Bi₂S₃ is diffused on the surface of Bi₄O₇ rod, enhancing the visible light response and improving the transport of photogenerated carriers. Various characterizations confirm that the rapid separation of photogenerated carriers leads to increased photocatalytic performance. The optimized Bi₂S₃/Bi₄O₇ heterostructure photocatalyst (BiS-0.15) exhibits the highest Cr(VI) reduction (0.01350 min⁻¹) and RhB oxidation (0.08011 min⁻¹) activity, which is much higher than that of pure Bi₄O₇ and Bi₂S₃/Bi₄O₇ mixture under visible light irradiation. This work provides new insights into the construction of efficient novel photocatalysts.     

One-pot synthesis of SrTiO3-SrCO3 heterojunction with strong interfacial electronic interaction as a novel photocatalyst for water splitting to generate H2

Photocatalytic hydrogen evolution from water splitting is a promising strategy for realizing the vision of carbon neutrality.Herein,a novel Sr Ti O₃-Sr CO₃n-n heterojunction was used for the first time for water splitting to generate H₂.The heterojunction was synthesized by a soft chemical one-pot hydrothermal method.The Sr Ti O₃-Sr CO₃loading with 3 wt%Pt shows the maximum photocatalytic H₂evolution rate of3.62 mmol h^-1     

Template‐free Fabrication of ZnS/TiO2 Photocatalyst with Macrochannels

Constructing a porous structure in photocatalysts is an effective strategy for improving the photocatalytic activity because of its enhanced molecule transfer capability and light capturing efficiency. In this work, a hierarchical macro‐/mesoporous ZnS/TiO₂ composite with macrochannels was successfully synthesized without using templates by the simple dropwise addition of an ethanol solution of tetrabutyl titanate and zinc acetate into a sodium sulfide aqueous solution, which was then calcined at 450°C. Compared with pure TiO₂, the ordered porous ZnS/TiO₂ composite exhibited an enhanced photocatalytic activity on methylene blue removal under UV‐light irradiation. The results indicate that the macro‐/mesoporous structure, the large specific surface area, and the heterostructure combination between ZnS and TiO₂ play a synergistic effect on the enhanced photocatalytic activity via improving the light absorption and the diffusion of organic molecules, providing more reactive sites for the photocatalytic reaction and improving the separation of photogenerated electron–hole pairs, respectively. Radical trapping experiments demonstrated that holes (h⁺) and superoxide anion radicals (O₂⁻) play an important role in the photocatalytic oxidation process.     

Lattice-matched in-situ construction of 2D/2D T-SrTiO3/CsPbBr3 heterostructure for efficient photocatalysis of CO2 reduction

The elaborate regulation of heterostructure interface to accelerate the interfacial charge separation is one of practicable approaches to improve the photocatalytic CO₂ reduction performance of halide perovskite (HP) materials. Herein, we report an in-situ growth strategy for the construction of 2D CsPbBr₃ based heterostructure with perovskite oxide (SrTiO₃) nanosheet as substrate (CsPbBr₃/SrTiO₃). Lattice matching and matchable energy band structures between CsPbBr₃ and SrTiO₃ endow CsPbBr₃/SrTiO₃ heterostructure with an efficient interfacial charge separation. Moreover, the interfacial charge transfer rate can be further accelerated by etching SrTiO₃ with NH₄F to form flat surface capped with Ti?O bonds. The resultant 2D/2D T-SrTiO₃/CsPbBr₃ heterostructure exhibits an impressive photocatalytic activity for CO₂ conversion with a CO yield of 120.2 ± 4.9 μmol g^?1 h^?1 at the light intensity of 100 mW/cm² and water as electron source, which is about 10 and 7 times higher than those of the pristine SrTiO₃ and CsPbBr₃ nanosheets, surpassing the reported halide perovskite-based photocatalysts under the same conditions.     

CoxP/Hollow Porous C3N4 as Highly Efficient Schottky Contact Photocatalyst for H2 Evolution from Water Splitting

Photocatalytic water splitting to obtain hydrogen energy can transform low-density solar to high density, new and clean energy in a clean way, which is one of the ideal ways to solve the energy crisis and environmental pollution. In this paper, The Co_xP/hollow porous C₃N₄ composite photocatalytic material was synthesized by simple methods. The photocatalytic hydrogen production rate of Co_xP/hollow porous C₃N₄ reaches 1602 μmol g⁻¹ h⁻¹, which is 151 times of that of pure C₃N₄. The reasons for the high photocatalytic H₂ evolution activity of Co_xP/hollow porous C₃N₄ could be summarized as follows: (1) the hollow and porous structure of C₃N₄ shows higher light capture efficiency, larger specific surface area and more surface active sites. (2) metalloid Co_xP loaded forms the Schottky contact with C₃N₄, which improves the photogenerated charges separation efficiency of C₃N₄, prolongs the photogenerated charges lifetime and improves the photocatalytic H₂ evolution activity of C₃N₄. (3) The higher conductivity of metalloid Co_xP and the lower overpotential of hydrogen production are other reasons for the higher activity of photocatalytic hydrogen production of Co_xP/hollow porous C₃N₄. This work provides an important role for the design of efficient, stable, and efficient construction of photocatalysts for solar energy conversion.     

Porous TiO2 Nanotubes with Spatially Separated Platinum and CoOx Cocatalysts Produced by Atomic Layer Deposition for Photocatalytic Hydrogen Production

Efficient separation of photogenerated electrons and holes, and associated surface reactions, is a crucial aspect of efficient semiconductor photocatalytic systems employed for photocatalytic hydrogen production. A new CoO_x/TiO₂/Pt photocatalyst produced by template‐assisted atomic layer deposition is reported for photocatalytic hydrogen production on Pt and CoO_x dual cocatalysts. Pt nanoclusters acting as electron collectors and active sites for the reduction reaction are deposited on the inner surface of porous TiO₂ nanotubes, while CoO_x nanoclusters acting as hole collectors and active sites for oxidation reaction are deposited on the outer surface of porous TiO₂ nanotubes. A CoO_x/TiO₂/Pt photocatalyst, comprising ultra‐low concentrations of noble Pt (0.046 wt %) and CoO_x (0.019 wt %) deposited simultaneously with one atomic layer deposition cycle, achieves remarkably high photocatalytic efficiency (275.9 μmol h⁻¹), which is nearly five times as high as that of pristine TiO₂ nanotubes (56.5 μmol h⁻¹). The highly dispersed Pt and CoO_x nanoclusters, porous structure of TiO₂ nanotubes with large specific surface area, and the synergetic effect of the spatially separated Pt and CoO_x dual cocatalysts contribute to the excellent photocatalytic activity.     

Polar Aromatic Two-dimensional Dion-Jacobson Halide Perovskites for Efficient Photocatalytic H2 Evolution

Polar materials with spontaneous polarization (P_s) have emerged as highly promising photocatalysts for efficient photocatalytic H₂ evolution owing to the P_s-enhanced photogenerated carrier separation. However, traditional inorganic polar materials often suffer from limitations such as wide band gaps and poor carrier transport, which hinders their photocatalytic H₂ evolution efficiency. Here, we rationally synthesized a series of isostructural two-dimensional (2D) aromatic Dion–Jacobson (DJ) perovskites, namely (2-(2-Aminoethyl)pyridinium)PbI₄ (2-APDPI), (3-(2-Aminoethyl)pyridinium)PbI₄ (3-APDPI), and (4-(2-Aminoethyl)pyridinium)PbI₄ (4-APDPI), where 2-APDPI and 4-APDPI crystalize in polar space groups with piezoelectric constants (d₃₃) of approximately 40 pm V⁻¹ and 3-APDPI adopts a centrosymmetric structure. Strikingly, owing to the P_s-facilitated separation of photogenerated carriers, polar 2-APDPI and 4-APDPI exhibit a 3.9- and 2.8-fold increase, respectively, in photocatalytic H₂ evolution compared to the centrosymmetric 3-APDPI. As a pioneering study, this work provides an efficient approach for exploring new polar photocatalysts and highlights their potential in promoting photocatalytic H₂ evolution.     

Construction of Hierarchical Hollow Co9S8/ZnIn2S4 Tubular Heterostructures for Highly Efficient Solar Energy Conversion and Environmental Remediation

Visible‐light‐responsive hierarchical Co₉S₈/ZnIn₂S₄ tubular heterostructures are fabricated by growing 2D ZnIn₂S₄ nanosheets on 1D hollow Co₉S₈ nanotubes. This design combines two photoresponsive sulfide semiconductors in a stable heterojunction with a hierarchical hollow tubular structure, improving visible‐light absorption, yielding a large surface area, exposing sufficient catalytically active sites, and promoting the separation and migration of photogenerated charges. The hierarchical nanotubes exhibit excellent photocatalytic H₂ evolution and Cr^VI reduction efficiency. Under visible‐light illumination, the optimized Co₉S₈/ZnIn₂S₄ heterostructure provides a remarkable H₂ generation rate of 9039 μmol h^?1 g^?1 without the use of any co‐catalysts and Cr^VI is completely reduced in 45 min. The Co₉S₈/ZnIn₂S₄ heterostructure is stable after multiple photocatalytic cycles.     

Direct electrospinning method for the construction of Z-scheme TiO2/g-C3N4/RGO ternary heterojunction photocatalysts with remarkably ameliorated photocatalytic performance

A series of Z-scheme TiO₂/g-C₃N₄/RGO ternary heterojunction photocatalysts are successfully constructed via a direct electrospinning technique coupled with an annealing process for the first time. They are investigated comprehensively in terms of crystal structure, morphology, composition, specific surface area, photoelectrochemical properties, photodegradation performance, etc. Compared with binary TiO₂/g-C₃N₄ and single-component photocatalysts, ternary heterojunction photocatalysts show the best photodegradation performance for RhB under stimulated sunlight. This can be attributed to the enlarged specific surface area (111.41 m²/g), the formation of Z-scheme heterojunction, and the high separation migration efficiency of photoexcited charge carriers. A potential Z-scheme mechanism for ternary heterojunction photocatalysts is proposed to elucidate the remarkably ameliorated photocatalytic performance based on active species trapping experiments, PL detection test of hydroxyl radicals, and photoelectrochemical properties.     

Semi-chemical interaction between graphitic carbon nitride and Pt for boosting photocatalytic hydrogen evolution

Owing to the exorbitant overpotential and serious carrier recombination of graphitic carbon nitride （gC₃N₄）,noble metal （NM） is usually served as the H₂evolution co-catalyst.Although the NM （such as Pt）nanoparticles can reduce the H₂evolution overpotential,the weak van der Waals interaction between Pt and g-C₃N₄makes against the charge transfer.Herein,the solvothermal method is developed to achieve semi-chemical interaction betwee...     

Band-Gap and Charge Transfer Engineering in Red Phosphorus-Based Composites for Enhanced Visible-Light-Driven H2 Evolution

It is known that the low lifetime of photogenerated carriers is the main drawback of elemental photocatalysts. Therefore, a facile and versatile one-step strategy to simultaneously achieve the oxygen covalent functionalization of amorphous red phosphorus (RP) and in situ modification of CdCO₃ is reported. This strategy endows RP with enhanced charge carrier separation ability and photocatalytic activity by coupling band-gap engineering and heterojunction construction. The as-prepared nCdCO₃/SO-RP (n=0.1, 0.25, 0.5, 1.0) composites exhibited excellent photocatalytic H₂ evolution activity (up to 516.3 μmol g⁻¹ h) from visible-light-driven water splitting (λ>400 nm), which is about 17.6 times higher than that of pristine RP. By experimental and theoretical investigations, the roles of surface oxygen covalent functionalization, that is, prolonging the lifetime of photogenerated carriers and inducing the negative shift of the conduction band potential, were studied in detail. Moreover, the charge transfer mechanism of these composites has also been proposed. In addition, these composites are stable and can be reused at least for three times without significant activity loss. This work may provide a good example of how to promote the activity of elemental photocatalysts by decorating their atomic structure.     

Promotion of photocatalytic steam reforming of methane over Ag~0/Ag~+-SrTiO_3

Methane(CH_4) is not only used as a fuel but also as a promising clean energy source for hydrogen generation.The steam reforming of CH4(SRM) using photocatalysts can realize the production of syngas(CO+H_2) with low energy consumption.In this work,Ag~0/Ag~+-loaded SrTi03 nanocomposites were successfully prepared through a photodeposition method.When the loading amount of Ag is 0.5 mol%,the atom ratio of Ag~+ to Ag~0 was found to be 51:49.In this case,a synergistic effect of Ago and Ag~+ was observed,in which Ago was proposed to improve the adsorption of H_2 O to produce hydroxyl radicals and enhance the utilization of light energy as well as the separation of charge carriers.Meanwhile,Ag~0 was regarded as the reduction reaction site with the function of an electron trapping agent.In addition,Ag~+adsorbed the CH4 molecules and acted as the oxidation reaction sites in the process of photocatalytic SRM to further promote electron-hole separation.As a result,0.5 mol% Ag-SrTi03 exhibited enhancement of photocatalytic activity for SRM with the highest CO production rate of 4.3 μmol g~(-1) h~(-1),which is ca.5 times higher than that of pure SrTi03.This work provides a facile route to fabricate nanocomposite with cocatalyst featuring different functions in promoting photocatalytic activity for SRM.     

In‐situ Platinum Plasmon Resonance Effect Prompt Titanium Dioxide Nanocube Photocatalytic Hydrogen Evolution

Herein, Pt‐decorated TiO₂ nanocube hierarchy structure (Pt‐TNCB) was fabricated by a facile solvothermal synthesis and in‐situ photodeposition strategy. The Pt‐TNCB exhibits an excellent solar‐driven photocatalytic hydrogen evolution rate (337.84 μmol h^?1), which is about 37 times higher than that of TNCB (9.19 μmol h^?1). Interestingly, its photocatalytic property is still superior to TNCB with post modification Pt (1 wt %) (208.11 μmol h^?1). The introduction of Pt efficiently extends the photoresponse of the composite material from UV to visible light region, simultaneously boosting their solar‐driven photocatalytic performance, which attribute to the porous structure, the sub size TNCB, the SPR effect of Pt NPs and strong interaction of two components. In fact, Pt NPs can enhance collective oscillations on delocalized electrons, which is conducive to capture electrons and hinder the recombination of photogenerated electron‐hole pairs, leading to the longer lifetime of photogenerated charges. The fabrication of Pt‐TNCB photocatalyst with SPR effect may provide a promising method to improve visible‐light photocatalytic activities for traditional photocatalysts.     

Synthesis of eco-friendly porous g-C3N4/SiO2/SnO2 composite with excellent visible-light responsive photocatalysis

Forming eco-friendly heterojunction photocatalysts is excellent method to accelerate the separation rate of photogenerated charge carriers, which is attracting more and more attention. In this study, a novel and stable disordered porous g-C₃N₄/SiO₂/SnO₂ (DOP-CSiSn) heterojunction composites was fabricated by a sol-gel hard template method, and the optimal g-C₃N₄ doped ratio was adjusted in DOP-CSiSn. The DOP-CSiSn photocatalyst had the much larger specific surface area and disordered porous structure, which exhibited strong photocatalytic effect to degrade Rhodamine B (RhB), Methylene blue (MB) and Methyl orange (MO) under visible light. When the g-C₃N₄ doping content was 30 wt%, the highest photocatalytic activities were obtained, and the degradation rate of MB and MO were 99.73% and 95.58% after 50 min, respectively. Degradation rate of RhB was 95.10% after 90 min. Photocatalytic degradation rate of organic pollutants were still more than 90% after six time consecutive cycles, the composite had wonderful stability and potential value in environmental purification.     

Z-Scheme In2S3/NU-1000 Heterojunction for Boosting Photo-Oxidation of Sulfide into Sulfoxide under Ambient Conditions

Photocatalytic oxidation of sulfide into sulfoxide has attracted extensive attention as an environmentally friendly strategy for chemical transformations or toxic chemicals degradation. Herein, we construct a series of In₂S₃/NU-1000 heterojunction photocatalysts, which can efficiently catalyze the oxidation of sulfides to form sulfoxides as the sole product under LED lamp (full-spectrum) illumination in air at room temperature. Especially, the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), can also be photocatalytically oxidized with In₂S₃/NU-1000 to afford nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) selectively and effectively. In contrast, individual NU-1000 and In₂S₃ show very low catalytic activity on this reaction. The significantly improved photocatalytic activity is ascribed to the constructing of an efficient Z-scheme photocatalysts In₂S₃/NU-1000, which exhibits the enhancement of light harvesting, the promotion of photogenerated electron-hole separation, and the retention of high porosity of the parent MOF. Moreover, mechanism studies in photocatalytic oxidation reveal that the superoxide radical (^.O₂⁻) and singlet oxygen (¹O₂) are the main oxidative species in the oxidation system. This work exploits the opportunities for the construction of porous Z-scheme photocatalysts based on the photoactive MOFs materials and inorganic semiconductors for promoting catalytic organic transformations. More importantly, it provides a route to the rational design of efficient photocatalysts for the detoxification of mustard gas.     

Enhancement of SrTiO<Subscript>3</Subscript>/BiPO<Subscript>4</Subscript> heterostructure for simulated organic wastewater degradation under UV light irradiation

A novel SrTiO₃/BiPO₄ heterostructure with different amounts of SrTiO₃ have been successfully prepared through the hydrothermal process. The photocatalysts were characterized by X-ray powder diffraction, UV–Vis diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic performance was evaluated by degrading the methylene blue dye solution under UV light. Results showed that the samples displayed excellent photocatalytic degradation efficiency due to the highly efficient suppression of the recombination of electron–hole pairs. A possible mechanism of SrTiO₃/BiPO₄ heterojunctions was discussed. The research indicated that the as-prepared SrTiO₃/BiPO₄ heterogeneous photocatalyst can be used as an effective material for degrading industrial organic wastewater.     

Engineering the Atomic Interface with Single Platinum Atoms for Enhanced Photocatalytic Hydrogen Production

It is highly desirable but challenging to optimize the structure of photocatalysts at the atomic scale to facilitate the separation of electron–hole pairs for enhanced performance. Now, a highly efficient photocatalyst is formed by assembling single Pt atoms on a defective TiO₂ support (Pt₁/def‐TiO₂). Apart from being proton reduction sites, single Pt atoms promote the neighboring TiO₂ units to generate surface oxygen vacancies and form a Pt‐O‐Ti³⁺ atomic interface. Experimental results and density functional theory calculations demonstrate that the Pt‐O‐Ti³⁺ atomic interface effectively facilitates photogenerated electrons to transfer from Ti³⁺ defective sites to single Pt atoms, thereby enhancing the separation of electron–hole pairs. This unique structure makes Pt₁/def‐TiO₂ exhibit a record‐level photocatalytic hydrogen production performance with an unexpectedly high turnover frequency of 51423 h^?1, exceeding the Pt nanoparticle supported TiO₂ catalyst by a factor of 591.     

A Fully Conjugated Covalent Organic Framework with Oxidative and Reductive Sites for Photocatalytic Carbon Dioxide Reduction with Water

Constructing a powerful photocatalytic system that can achieve the carbon dioxide (CO₂) reduction half-reaction and the water (H₂O) oxidation half-reaction simultaneously is a very challenging but meaningful task. Herein, a porous material with a crystalline topological network, named viCOF-bpy-Re, was rationally synthesized by incorporating rhenium complexes as reductive sites and triazine ring structures as oxidative sites via robust −C=C− bond linkages. The charge-separation ability of viCOF-bpy-Re is promoted by low polarized π-bridges between rhenium complexes and triazine ring units, and the efficient charge-separation enables the photogenerated electron–hole pairs, followed by an intramolecular charge-transfer process, to form photogenerated electrons involved in CO₂ reduction and photogenerated holes that participate in H₂O oxidation simultaneously. The viCOF-bpy-Re shows the highest catalytic photocatalytic carbon monoxide (CO) production rate (190.6 μmol g⁻¹ h⁻¹ with about 100 % selectivity) and oxygen (O₂) evolution (90.2 μmol g⁻¹ h⁻¹) among all the porous catalysts in CO₂ reduction with H₂O as sacrificial agents. Therefore, a powerful photocatalytic system was successfully achieved, and this catalytic system exhibited excellent stability in the catalysis process for 50 hours. The structure–function relationship was confirmed by femtosecond transient absorption spectroscopy and density functional theory calculations.     

BiOBr/g-C3N4 S型异质结无H2O2光-自芬顿高效催化降解RhB

通过焙烧-超声混合法成功地制备了BiOBr/g-C₃N₄S型异质结复合光催化剂。采用多种表征手段对样品物理属性进行了表征,包括X射线多晶粉末衍射仪(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外可见漫反射光谱(UV-Vis DRS)。研究了所制备样品有/无Fe³⁺的光-自芬顿催化/光催化降解罗丹明B(RhB)性能。通过捕获实验确定了光催化反应中的主要活性物种,提出了光-自芬顿反应的降解机理。研究结果表明,BiOBr/g-C₃N₄S型异质结能原位生成H₂O₂,添加Fe³⁺后,H₂O₂被原位活化成活性物种且光生电流和载流子分离效率获得显著提高。该光-自芬顿过程能高效降解RhB,其反应速率常数为0.208 min^-1,约为无Fe³⁺光催化反应速率常数的5.3倍,在光-自芬顿循环使用过程中表现出良好的稳定性。Fe...     

BiOBr/g-C3N4 S型异质结无H2O2光-自芬顿高效催化降解RhB

通过焙烧-超声混合法成功地制备了BiOBr/g-C₃N₄ S型异质结复合光催化剂。采用多种表征手段对样品物理属性进行了表征,包括X射线多晶粉末衍射仪(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外可见漫反射光谱(UV-VisDRS)。研究了所制备样品有/无Fe³⁺的光-自芬顿催化/光催化降解罗丹明B (RhB)性能。通过捕获实验确定了光催化反应中的主要活性物种,提出了光-自芬顿反应的降解机理。研究结果表明,BiOBr/g-C₃N₄ S型异质结能原位生成H₂O₂,添加Fe³⁺后,H₂O₂被原位活化成活性物种且光生电流和载流子分离效率获得显著提高。该光-自芬顿过程能高效降解RhB,其反应速率常数为0.208 min^-1,约为无Fe³⁺光催化反应速率常数的5.3倍,在光-自芬顿循环使用过程中表现出良好的稳定性。Fe³⁺的加入促进了光生电荷的分离和H₂O₂的活化,超氧阴离子自由基(·O₂^-)、空穴和羟基是光-自芬顿催化过程中的主要活性物种,且·O₂^-作用更大。