Cd0.5Zn0.5S Research Articles

A S-scheme 0D/2D heterojunction formed by decorating Cd0.5Zn0.5S nanoparticles on Cu2MoS4 plates for efficient photocatalytic hydrogen generation

Rationally designing a Step-scheme (S-scheme) hetero-structured photocatalyst with high redox capability and separation efficiency of photoinduced carriers is considered as an attractive approach to address the shortcomings of single component and traditional hetero-structured photocatalyst. Herein, enlightened by the predictions of density functional theory (DFT), a unique S-scheme heterojunction photocatalyst was successfully fabricated by incorporating zero-dimensional (0D) Cd0.5Zn0.5S (CZS) on two-dimensional (2D) lamellar Cu2MoS4 (CMS) plates via a facile coprecipitation method, which substantially enhances the photocatalytic activity for hydrogen (H2) generation. CZS nanoparticles deposited on the surface of CMS nanoplates play a crucial role in creating highly intimate heterojunction interfaces and abundant exposed reaction sites, laying the foundation for improved photocatalytic performance. Furthermore, the significant difference in Fermi levels and band structures between CZS and CMS result in the formation of the internal electric field (IEF) and energy band bending at the interface of the heterojunction. This S-scheme charge transfer path enables 0D/2D CZS/CMS heterojunction possesses an exceptional capacity to maintain the robust redox potential and boosts the separation efficiency of light-induced carriers, as verified by DFT calculations and energy band structure analyses. As expected, the optimal heterojunction exhibits a satisfactory H2 generation rate of 13.1 mmol·g-1·h−1, which is nearly 7.7-fold higher than that of individual CZS. This study is expected to inspire the design of morphology-controlled hetero-structured photocatalyst with S-scheme charge transfer route for photocatalytic H2 generation.

Strain Engineering of Cd0.5Zn0.5S Nanocrystal for Efficient Photocatalytic Hydrogen Evolution from Wasted Plastic.

The challenge of synthesizing nanocrystal photocatalysts with adjustable lattice strain for effective waste-to-energy conversion is addressed in this study. Cd0.5Zn0.5S (CZS) nanocrystals are synthesized by a simple solvothermal method, regulation of the ratio between N, N-dimethylformamide, and water solvent are shown to provoke expansion and contraction, inducing an adjustable lattice strain ranging from -1.2% to 5.6%. With the hydrolyzed wasted plastic as a sacrificial agent, the 5.6% lattice-strain CZS exhibited a robust hydrogen evolution activity of 1.09mmol m-2h-1 (13.83mmol g-1h-1), 4.5 times that of pristine CZS. Characterizations and density functional theory calculation demonstrated that lattice expansion increases the spatial distance between the valence band maximum and conduction band minimum, thus reducing carrier recombination and promoting charge transfer. Additionally, lattice expansion induces surface S vacancies and adsorbed OH groups, further enhancing redox reactions. This study focuses on the synchronous regulation of crystal structure, charge separation/transport, and surface reactions through lattice strain engineering, which providing a reference for the rational design of new photocatalysts for effective waste-to-energy conversion.

Synthesize magnetic ZnFe2O4@C/Cd0.9Zn0.1S catalysts with S-scheme heterojunction to achieve extraordinary hydrogen production efficiency

Suppressing the electron-hole recombination rate of catalyst legitimately is one of the effective strategies to improve photocatalytic hydrogen evolution. Herein, carbon-coated metal oxide, ZnFe2O4@C (ZFO@C), nanoparticles were synthesized and employed to couple with quadrupedal Cd0.9Zn0.1S (CZS) via an ordinary ultrasonic self-assembly method combined with calcination to form a novel ZFO@C/CZS catalyst with step-scheme (S-scheme) heterojunction. The photocatalytic hydrogen evolution reaction (HER) was conducted to verify the enhanced photoactivity of ZFO@C/CZS. The optimal ZFO@C/CZS exhibits an extraordinary photocatalytic HER rate of 111.3 ± 0.9 mmol g-1 h−1 under visible-light irradiation, corresponding to an apparent quantum efficiency as high as (76.2 ± 0.9)% at 450 nm. Additionally, the as-synthesized ZFO@C/CZS composite exhibits high stability and recyclability. The excellent photocatalytic hydrogen evolution performance should arise from the formed S-scheme heterojunction and the unique ZFO@C core–shell structure, which inhibit electron hole recombination as well as provide more reactive sites. The pathway of S-scheme charge transfer was validated through density functional theory calculations and electrochemical measurements. This work provides a rational strategy for the synthesis of unique magnetic S-scheme heterojunction photocatalysts for water splitting under visible light irradiation.

Hollow-shell hybrids with regulatable microelectronic structures for boosting photocatalytic H2 evolution via water splitting and isopropanol oxidation under visible light

Herein, a series of heteroatoms doped-NMIL(Ti)/Cd0.5Zn0.5S are synthesized, where the Cd0.5Zn0.5S (CZS) uniformly grows in situ on the surface of NMIL(Ti) encapsulating ultra-trace Cu/Fe/Co atoms to form the mesoporous hollow-shell structures. The microelectronic structures of photocatalysts can be modulated via regulatable band potential of Cu/Fe/Co-doped NMIL(Ti) due to the intense interaction between heteroatoms and −NH2 groups. Moreover, the Ti3+-oxygen vacancy pairs as the photogenerated electron library and the heterojunction effectively facilitate the special separation and migration of carriers. The optimal hybrid (Cu1%-NMIL(Ti)/CZS) has a photocatalytic hydrogen evolution rate of 251.2 μmol g−1 (12,560.12 μmol g−1 h−1) in 0.35 M Na2S/0.25 M Na2SO3 under visible light, which is 4.34 and 1.74 times higher than that of CZS and NMIL(Ti)/CZS, respectively. Moreover, the H2 yield reaches 29,860 μmol g−1 h−1 in 0.35 M Na2S/0.25 M Na2SO3/2 M isopropanol system, which is 2.38 times than before, displaying that isopropanol oxidation not only consumes photo-holes to inhibit carries recombination, but also provides H+ to participate in H2 production. This work provides a new insight for developing a high-efficiency photocatalytic H2 evolution system.

Incorporating Ni-Polyoxometalate into the S-Scheme Heterojunction to Accelerate Charge Separation and Resist Photocorrosion for Promoting Photocatalytic Activity and Stability.

The emerging polyoxometalate (POM) nanomaterials are transition metal oxygen anion clusters with d0 electronic configurations, which could be attractive and potential photocatalysts. Hence, a nickel (Ni)-substituted polyoxometalate K6Na4[Ni4(H2O)2(PW9O34)2]·32H2O (Ni4POM)-incorporating step (S)-scheme heterojunction was developed to promote photocatalytic activity and stability in H2 and H2O2 production. The multielectron transfer through variable valence metal centers in Ni4POM would facilitate the recombination of invalid charges through the S-scheme pathway. Moreover, incorporating Ni4POM into the S-scheme heterojunction can broaden the light absorption range and meanwhile lead to resistance to photocorrosion to promote the optical and chemical stability of Cd0.5Zn0.5S (CZS). The optimized CZSNi-70 exhibited a H2 evolution rate of 42.32 mmol g-1 h-1 under visible-light irradiation with an apparent quantum yield of 32.27% at 420 nm and a H2O2 production rate of 295.4 μmol L-1 h-1 under 420 nm light-emitting diode irradiation. This work can provide a new view for the development of transition metal-substituted POM-based stable and efficient S-scheme photocatalysts.

Plasmonic Ni3N Cocatalyst Boosting Directional Charge Transfer and Separation toward Synergistic Photocatalytic-Photothermal Performance of Hydrogen and Benzaldehyde Production as Well as Bacterial Inactivation.

Charge separation and transfer are the dominating factors in achieving high activity of solar energy-based photocatalysis. Here, a plasmonic transition metal nitride, Ni3N, nanosheet was fabricated and employed as an efficient cocatalyst to couple with Cd0.9Zn0.1S (CZS) solid solution via a self-assembly method to form a novel Ni3N/CZS heterojunction with an intimate interface. On one hand, localized surface plasmon resonance of the Ni3N nanosheets endowed the fabricated Ni3N/CZS composite with a wide-spectrum light absorption capacity, even to the near-infrared range. On the other hand, Ni3N as a cocatalyst can not only effectively induce the directional electron transfer from CZS to Ni3N active sites but also enhance the surface charge separation efficiency of the Ni3N/CZS heterojunction by 4.1 times compared to that of pure CZS. Plasmonic Ni3N also provided a photothermal effect to enhance the surface temperature of the composite for boosting the catalytic reaction kinetics. As a result, under visible light irradiation, the optimal Ni3N/CZS composite exhibited simultaneous H2 generation and benzaldehyde formation rates of 35.08 and 16.44 mmol g-1 h-1, which were 9.4 and 5.9 times those of CZS, respectively; and the composite also demonstrated a strong antibacterial ability with a sterilization rate of 99.7% toward Escherichia coli. Besides that, under NIR light, plasmonic Ni3N offered extra hot electrons that can transfer back to CZS to take part in the photocatalytic reaction, leading to the Ni3N/CZS composite still having a high H2 production of 179.6 μmol g-1 h-1. This work focuses on developing and applying novel plasmonic cocatalysts in photocatalysis for achieving adjustable electron transfer and fast charge separation for extensive practical application.

PdS Quantum Dots as a Hole Attractor Encapsulated into the MOF@Cd0.5Zn0.5S Heterostructure for Boosting Photocatalytic Hydrogen Evolution under Visible Light.

Herein, a new photocatalyst PdS@UiOS@CZS is successfully synthesized, where thiol-functionalized UiO-66 (UiOS), a metal-organic framework (MOF) material, is used as a host to encapsulate PdS quantum dots (QDs) in its cages, and Cd0.5Zn0.5S (CZS) solid solution nanoparticles (NPs) are anchored on its outer surface. The resultant PdS@UiOS@CZS with an optimal ratio between components displays an excellent photocatalytic H2 evolution rate of 46.1 mmol h-1 g-1 under visible light irradiation (420∼780 nm), which is 512.0, 9.2, and 5.9 times that of pure UiOS, CZS, and UiOS@CZS, respectively. The reason for the significantly enhanced performance is that the encapsulated PdS QDs strongly attract the photogenerated holes into the pores of UiOS, while the photogenerated electrons are effectively migrated to CZS due to the heterojunction effect, thereby effectively suppressing the recombination of charge carriers for further high-efficiency hydrogen production. This work provides an idea for developing efficient photocatalysts induced by hole attraction.

Noble-metal-free chalcogenide nanotwins for efficient and stable photocatalytic pure water splitting by surface phosphorization and cocatalyst modification

Chalcogenide photocatalysts are considered excellent candidates for photocatalytic water splitting because of their narrow bandgaps enabling utilization of visible light. However, severe self-oxidation of sulfide ions during water oxidation greatly restricts their application toward pure water splitting. Herein, we report the synthesis of a near-surface P-doped Cd0.5Zn0.5S (CZS) nanotwin photocatalyst, co-modified by red phosphorus (RP) and transition metal phosphides (TMPs, including FeP, Ni2P, and Co2P) by a one-step phosphorization method that enables efficient and stable pure water splitting. We demonstrate that homogenous phosphorus bridges formed from CZS to both RP and TMP because of near-surface P doping. These unique bridges enable effective charge transfer from RP to CZS and then to TMP via a two-electron Z-scheme mechanism. Significantly, the RP for photogenerated holes capture shows great corrosion–resistance during water oxidation, with simultaneous production of H2O2, while TMP promotes H2 evolution. The optimal CZS-P-Co2P shows a H2 evolution rate of 801.3 μmol/h/g for visible-light-driven pure water splitting, with an apparent quantum of 7.46% at 400 nm, which are among the highest reported values over chalcogenide photocatalysts. This work demonstrates the promising application potential of chalcogenides as photocatalysts for pure water splitting.

A new type of photoinduced Anion-Exchange Approach: MOF-Derived Cobalt-Based sulfide enables spatial separation of catalytic sites for efficient H2 photoproduction

The high- and low-dimensional cross-structure catalyst enables activating more reaction sites and separates the reduction and oxidation sites in space, thus achieving efficient catalytic reactions. Herein, we develop metal–organic frameworks (MOFs) derivatives with a complete skeleton as high-dimensions cocatalysts under mild conditions. That is, using zeolitic imidazolate frameworks (ZIF-67) as a sacrificial template, a flower-like amorphous CoSx cocatalyst (CoSx-C/N) assembled from two-dimensional (2D) nanosheets rich in C/N is prepared by a new type of photoinduced anion-exchange approach and supported on one-dimensional (1D) Cd0.5Zn0.5S (CZS) catalyst. The formation of unique high- and low-dimensional cross-structure 2D@1D composite photocatalyst (designated as CoSx-C/Ny@CZS). In addition, the Co-S-C/N charge channel is introduced. Such structure can result in both the dispersion of the active sites and an increase in the charge transfer rate. As a result, CoSx-C/N2@CZS has better activity (18.57 mmolg−1h−1) than CZS (7.90 mmolg−1h−1) under visible light irradiation and the quantum yield reaches 21.05% at 420 nm excitation. This work emphasizes utilizing the characteristic of photochemical instability of Co-MOF for cocatalyst design to achieve high photo-charge transfer efficiency and sufficient reaction kinetics, thereby enhancing hydrogen photoproduction performance.

Surface assembly of cobalt species for simultaneous acceleration of interfacial charge separation and catalytic reactions on Cd0.9Zn0.1S photocatalyst

Although photocatalytic water splitting has excellent potential for converting solar energy into chemical energy, the challenging charge separation process and sluggish surface catalytic reactions significantly limit progress in solar energy conversion using semiconductor photocatalysts. Herein, we demonstrate a feasible strategy involving the surface assembly of cobalt oxide species (CoOx) on a visible-light-responsive Cd0.9Zn0.1S (CZS) photocatalyst to fabricate a hierarchical CZS@CoOx heterostructure. The unique hierarchical structure effectively accelerates the directional transfer of photogenerated charges, reducing charge recombination through the smooth interfacial heterojunction between CZS and CoOx, as evidenced by photoluminescence (PL) spectroscopy and various electrochemical characterizations. The surface cobalt species on the CZS material also act as efficient cocatalysts for photocatalytic hydrogen production, with activity even higher than that of noble metals. The well-defined CZS@CoOx heterostructure not only enhances the interfacial separation of photoinduced charges, but also improves surface catalytic reactions. This leads to superior photocatalytic performances, with an apparent quantum efficiency of 20% at 420 nm for visible-light-driven hydrogen generation, which is one of the highest quantum efficiencies measured among noble-metal-free photocatalysts. Our work presents a potential pathway for controlling complex charge separation and catalytic reaction processes in photocatalysis, guiding the practical development of artificial photocatalysts for successful transformation of solar to chemical energy.

Integrated Z-Scheme Nanosystem Based on Metal Sulfide Nanorods for Efficient Photocatalytic Pure Water Splitting.

Developing efficient metal sulfides for pure water splitting is a challenging topic in the field of photocatalysis. Herein, inspired by natural photosynthesis, an all-solid-state Z-scheme photocatalyst was constructed with Cd0.9 Zn0.1 S (CZS) for water reduction, red phosphorus (RP) for water oxidation, and metallic CoP as the electron mediator. RP@CoP core-shell nanostructures were uniformly attached on the CZS nanorods, which gave rise to multiple monodispersed nanojunctions. The integrated Z-scheme nanosystem exhibited an apparent quantum efficiency of 6.4 % at 420 nm for pure water splitting. Theoretical analysis and femtosecond transient absorption results revealed that the impressive performance was mainly due to efficient hole transfer of CZS, resulting from the intimate atomic contacts between CoP mediator and photocatalysts, together with favorable band alignment. Meanwhile, the multiple monodispersed Z-scheme nanojunctions could provide abundant reaction sites, which was also important for the boosted activity.

Fabrication of layered Fe2P-Cd0.5Zn0.5S nanoparticles with a reverse heterojunction for enhanced photocatalytic hydrogen evolution

In this work, a novel two-dimensional (2D) layered Fe2P modified Cd0.5Zn0.5S (CZS) nanoparticles composites were successfully developed by an environmentally friendly solvothermal method. The Fe2P-CZS photocatalysts were used for noble-metal-free photocatalytic H2 generation under visible light. The rate of H2 evolution of 13 wt% Fe2P-CZS was 24.84 mmol·g−1·h−1, which was 37.6 times that of CZS (0.66 mmol·g−1·h−1). The formation of the 2D-0D reverse heterojunction in the Fe2P-CZS composite photocatalyst improved the transport and separation of photogenerated electron-hole pairs and optimized the kinetics of hydrogen evolution. Compared with Fe2P particles, the layered Fe2P cocatalysts had higher conductivity and lower hydrogen evolution overpotential.

Coralline-like Ni2P decorated novel tetrapod-bundle Cd0.9Zn0.1S ZB/WZ homojunctions for highly efficient visible-light photocatalytic hydrogen evolution

In this study, Ni2P-Cd0.9Zn0.1S (NPCZS) composites were synthesized by coupling tetrapod bundle Cd0.9Zn0.1S (CZS) and coralline-like Ni2P (NP) via a simple calcination method. CZS shows outstanding activity in photocatalytic hydrogen evolution (1.31 mmol h−1), owing to its unique morphology and heterophase homojunctions (ZB/WZ), which accelerate the separation and transfer of photogenerated charges. After coupling with NP, the photoactivity of NPCZS was enhanced, and the maximum hydrogen evolution rate of 1.88 mmol h−1 was reached at a NP content of 12 wt%, which was 1.43 times higher than that of pure CZS. The experimental results of the photocatalytic activity, viz. photoluminescence spectra, surface photovoltage spectra, and electrochemical test showed that the enhanced photoactivity of NPCZS should be attributed to the synergistic effects of the novel tetrapod-bundle morphology, heterophase homojunctions, and decoration of the NP co-catalyst. Moreover, the as-prepared NPCZS composites exhibited excellent photostability and recyclability. Herein, we propose a possible mechanism for the enhanced photocatalytic activity.

Constructing Ni2P/Cd0.5Zn0.5S/Co3O4 ternary heterostructure for high-efficient photocatalytic hydrogen production

Constructing heterostructure for efficient charge separation is a hopeful way for enhance photocatalytic hydrogen production. In this paper, we successfully construct the Ni2P/Cd0.5Zn0.5S/Co3O4 (Ni2P/CZS/Co3O4) heterostructure via three-step hydrothermal method. It is demonstrated that Ni2P/CZS/Co3O4 shows a prominent photocatalytic H2 generation activity of 39.66 mmol g−1 h−1, revealing about 2.42 times enhancement compared to that of the pure Cd0.5Zn0.5S (CZS) under visible light. The closely contacted CZS/Co3O4 forms a type-II heterostructure to accelerate the separation of photoinduced charge. The Ni2P acts as electron traps to capture the photoelectrons, and provide active sites for proton reduction. Moreover, the cooperative synergy of type-II heterostructure and active sites achieves an obvious improvement for photocatalytic hydrogen production.

Cd0.5Zn0.5S/Ni2P noble-metal-free photocatalyst for high-efficient photocatalytic hydrogen production: Ni2P boosting separation of photocarriers

Establishing efficient co-catalytic loaded semiconductors for efficient charge separation is a hopeful way for enhance photocatalytic water splitting hydrogen evolution. Herein, we successfully constructed the Cd0.5Zn0.5S/Ni2P (CZS/Ni2P) nanocomposites via two-step hydrothermal method. The CZS/Ni2P composites show much improved activity than the origin CZS for photocatalytic H2 generation. When the content of Ni2P loaded on the Cd0.5Zn0.5S (CZS) is 0.3 mol%, the photocatalyst achieves the highest photocatalytic hydrogen generation rate of 41.26 mmol g−1 h−1 under visible light. The Ni–S bonds on the close contact interface between CZS and Ni2P can be act as electron-bridge to provide a channel for electron transfer. During the photocatalysis processing, Ni2P can be used as electron traps to attract electrons from CZS, resulting in the improvement of the photocatalytic performance.

Potassium-doped-C3N4/Cd0.5Zn0.5S photocatalysts toward the enhancement of photocatalytic activity under visible-light

The construction of new semiconductor photocatalysts toward the enhancement of photocatalytic activity under visible-light is crucial for a sustainable and clean future. In this paper, cation doping and heterojunction construction were synergistically used to synthesize g-C3N4 matrix composite with a narrow band gap and low recombination rate of photogenerated electron-hole pairs. Potassium-doped-C3N4 (KCN) was used as the matrix to construct semiconductor heterojunction with Cd0.5Zn0.5S (CZS) by hydrothermal method. The resulting composites were characterized through X-ray diffraction, infrared radiation, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and ultraviolet–visible diffuse reflectance spectroscopy techniques to examine its phase structure, morphological, valance state and optical properties respectively. The photocatalytic performance of the samples evaluated by H2 evolution and degrading the Rhodamine B (RhB) aqueous solution. After 12 h hydrothermal reaction at 140 °C, CZS particles uniformly distributed on the KCN matrix. The photocatalytic hydrogen production rate (HPR) of the sample loaded 24 wt% CZS (KCN/CZS 24 wt%) reaches 1.83 mmol/g·h which is 5.6 times of pristine g-C3N4. The degradation rate constant on RhB of KCN/CZS 24 wt% is (k = 0.041 min−1) 7.9 times higher than g-C3N4. The enhanced photocatalytic activity can be attributed to the well-matched energy level of KCN and CZS as well as the extended light absorption of the composites.

Carbon quantum dots bridged TiO2 and Cd0.5Zn0.5S film as solid-state Z-scheme photocatalyst with enhanced H2 evolution activity

Abstract Traditional type II heterojunction photocatalyst usually has excellent activities due to the improved charge transfer between the matched band structures of each component, but this is also accompanied by reducing the oxidation–reduction capability of electrons and holes. Z-scheme system is demonstrated to be effective on maximizing the advantages of each photocatalyst. In this work, a novel Z-scheme heterojunction photocatalyst containing TiO2 nanofilm, Carbon Quantum Dots (CQDs) and Cd0.5Zn0.5S (CZS) nanoparticles (CZS/C/TiO2 nanofilm) was fabricated by hydrothermal method and an in situ reflux reaction process. The existence of CQDs results in a direct combination of electrons and holes from the CB of TiO2 and VB of Cd0.5Zn0.5S, and retains the active electron and holes in this system. Besides, it also benefits from the excellent optical absorption and prolonging electron lifetime, the ternary system shows excellent activity during photocatalytic water splitting with a high H2 production rate of 38.74 mmol·h − 1·m − 2, which is 3.4 and 1.5 times higher than that of pure TiO2 and CZS/TiO2 type II heterojunction without CQDs. In addition, CQDs bridged semiconductors as all solid-state Z-scheme heterojunction exhibit good stability and reusability.

A novel magnetically separable CoFe2O4/Cd0.9Zn0.1S photocatalyst with remarkably enhanced H2 evolution activity under visible light irradiation

CoFe2O4/Cd0.9Zn0.1S (CFO/CZS) p-n junction photocatalysts were prepared by a simple calcination method. In the as-prepared CFO/CZS photocatalysts, the CoFe2O4 (CFO) nanoparticles were decorated on the surface of Cd0.9Zn0.1S (CZS) nanorods. The ferromagnetic property of the as-prepared CFO/CZS photocatalysts ensures their convenient recycling by an external magnetic field. CFO/CZS photocatalysts with the mass ratio of CFO to CZS of 7% showed the highest photocatalytic H2 evolution activity, the rate of 350.2 μmol/h, which is around 10 times higher than that of pure CZS with an apparent quantum efficiency of 27% at 420 nm. This remarkable enhancement of photocatalytic activity could be attributed to the highly efficient separation of photogenerated charge after the formation of p-n junctions. Moreover, as-synthesized CFO/CZS p-n junction photocatalysts showed strong magnetic recyclability and excellent photostability.

Enhanced Z-scheme visible light photocatalytic hydrogen production over α-Bi2O3/CZS heterostructure

Depletion of fossil fuels and associated environmental issues has drawn attention of researchers to renewable energy resources and photocatalytic hydrogen production is considered to be safe and applicable method to meet future energy demand. Herein, we have used α-Bi2O3 nanorods for loading CZS (Cd0.5Zn0.5S) to form a heterostructure for photocatalytic H2 production. The α-Bi2O3/CZS heterostructure was characterized through TEM, Elemental Mapping, XRD and XPS analysis. The α-Bi2O3/CZS heterostructure shows photocatalytic H2 production rate of 254.1 μmol h−1 with apparent quantum yield of 6.8% (λ = 420 nm). The enhanced photocatalytic performance was supported by transient photocurrent response curves and electrochemical impedance spectroscopy (EIS) results which suggest the efficient charge separation and electron mobility in α-Bi2O3/CZS heterostructure. The intimate contact formed between α-Bi2O3 nanorods and CZS nanoparticles responsible for the efficient flow of electrons following a Z-scheme pattern resulting in higher photocatalytic H2 production. Moreover, the as-synthesized α-Bi2O3/CZS heterostructure shows negligible loss of activity after 4 consecutive recycling cycles. Our findings open new possibilities for the design of heterostructure based photocatalysts.

Kilogram-scale production of highly active chalcogenide photocatalyst for solar hydrogen generation

Solar photocatalytic hydrogen production from water has been regarded as an ideal way addressing world energy and environmental crises. The technology has long relied on the development of an efficient photocatalyst. In addition to its photocatalytic performance, the large-scale production of certain photocatalyst from the viewpoint of particle application remains a challenge yet has received insufficient focus. Herein, we report an efficient and practical batch preparation system based upon hydrothermal method to the scalable production of chalcogenide nanoparticle photocatalyst. Taking the synthesis of Cd0.5Zn0.5S (CZS) twinned photocatalyst as an example, the outcome of CZS photocatalyst could reach ∼0.8 kg in this batched synthesis, which is about 390 times of the lab-scale production in mass amount. It was found that the twinned structure and visible-light absorption property were well maintained. Although further measurements toward the photocatalytic activity indicate slight decrement on solar H2 generation compared to the lab-scale synthesized CZS photocatalyst, a high quantum efficiency of about 40.5% at 425 nm remained. The photocatalytic reaction could also stably proceed for 200 h without notable decay of H2-evolution rate. This work thus provides a powerful means for facile scaling up the chalcogenide nanoparticle photocatalyst at the kilogram level with both high quality and good reproducibility.