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The synergistic effects derived from optimizing the chemical and structural features of electrocatalysts permit them to attain remarkable activity and stability. Herein, 1D/2D cobalt‐based nanohybrid (CoNH) electrodes are developed; the structural design consists of Co3O4 electrospun nanoribbons (NRs) deposited onto a carbon fiber paper substrate where Co3O4 nanosheets are subsequently grown via an electrodeposition step and UV/ozone treatment. The content of noncovalently functionalized carbon nanotubes within the Co3O4 NRs is first tuned to enhance their charge transfer properties and mechanical stability. The electrocatalytic activity of the electrodes is further improved by a phosphorus modification of the 1D NRs, resulting in the formation of NaCoPO4. The optimized 1D/2D CoNH electrode, i.e., ED‐0.09 wt% fCNTs/P‐CoNHs, displays a similar performance to that of platinum in 0.25 m Na2S/0.35 m Na2SO3 (Tafel slope ≈102 mV dec−1 for the former and ≈96 mV dec−1 for the latter) and outstanding stability for up to 48 h. The versatility and high activity of this electrode is also demonstrated according to tests in a conventional water splitting system (cell voltage 1.55V, to produce 10 mA cm−2) and a solar‐driven electrolyzer (1 m KOH). [ABSTRACT FROM AUTHOR]

The design and development of efficient nitride photocatalysts have attracted much attention. Herein, two-dimensional mesoporous Ta 3 N 5 is successfully synthesized through a simple sol-gel process with filter paper as a biological template and a combination of vacuum nitriding reactions. The prepared Ta 3 N 5 shows a wide light response range up to the near infrared (NIR) region due to the nitrogen vacancies generated from substitution of N3− for O2− ions during vacuum nitridation. Significantly, such a narrow bandgap (∼1.99 eV) still satisfies the redox potential of water splitting in thermodynamics. The experimental results show that the Ta 3 N 5 photocatalyst exhibits an enhanced hydrogen production rate of 34.6 μmol h−1 g−1, which is 3.9 and 2.1 times higher than that of Ta 2 O 5 and partial nitridation of Ta 2 O 5 (N–Ta 2 O 5), respectively. This enhanced photocatalytic performance could be attributed to the high specific surface area to provide reactive active sites, substitution of N3− for O2− ions to optimize the band structure, and special two-dimensional mesoporous structure to shorten the charge transfer distance. This work provides a new perspective for the preparation of two-dimensional nitride materials by a biological template method combining vacuum nitriding with enhanced photocatalytic performance. Two-dimensional mesoporous Ta 3 N 5 is synthesized by a simple sol-gel process with filter paper as a biological template and vacuum nitriding reaction, leading to an efficient photocatalytic performance. [Display omitted] • Two-dimensional mesoporous Ta 3 N 5 was prepared by a biological template. • The prepared Ta 3 N 5 shows a wide light response range up to the near infrared region. • The special two-dimensional structure shortens the charge transfer distance. • The Ta 3 N 5 photocatalyst shows a superior hydrogen production performance. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysis is a potential solution to meet energy needs with green and inexhaustible solar energy. However, designing efficient and stable photocatalysts is a challenging task due to the limited ability to effectively separate electrons and holes. In this paper, by using a straightforward ethanol dispersion technique, we were able to combine ultrathin layered Cu-TCPP MOFs with g-C3N4 nanosheets, resulting in the creation of an extremely effective nano-composite photocatalyst with exceptional UV-vis activity. CT/CN heterojunctions displayed remarkable photocatalytic efficacy for the production of H2, with 3CT/CN showcasing a five-fold enhancement in photoactivity as compared to the unadorned g-C3N4. Based on the results of photoluminescence spectroscopy, electrochemical impedance spectroscopy, and electrochemical reduction, the considerably improved charge transfer and separation, together with the possible catalytic capability of uniformly distributed metal nodes in Cu-TCPP, are believed to be the underlying reason for the observed exceptional photoactivity. After thorough analysis, a potential process for charge transfer and segregation between g-C3N4 and Cu-TCPP has been suggested. [ABSTRACT FROM AUTHOR]

Metal halide perovskites, such as iodine methylamine lead (MAPbI3), have received extensive attention in the field of photocatalytic decomposition of HI for hydrogen evolution, due to their excellent photoelectric properties. In this paper, a new MAPbI3-based composite, MoC/MAPbI3, was synthesized. The results show that 15 wt% MoC/MAPbI3 has the best hydrogen production performance (38.4 μmol h−1), which is approximately 24-times that of pure MAPbI3 (1.61 μmol h−1). With the extension of the catalytic time, the hydrogen production rate of MoC/MAPbI3 reached 165.3 μmol h−1 after 16 h due to the effective separation and transfer of charge carriers between MoC and MAPbI3, showing excellent hydrogen evolution rate performance under visible light. In addition, the cycling stability of MoC/MAPbI3 did not decrease in multiple 4 h cycle tests. This study used the non-precious metal promoter MoC to modify MAPbI3, and provides a new idea for the synthesis of efficient MAPbI3-based composite catalysts. [ABSTRACT FROM AUTHOR]

NiFe-LDH/g-C3N4 (LDH/CN) heterostructures with different amounts of NiFe-LDH (LDH) were prepared by a hydrothermal method and characterized using different experimental techniques. Their photocatalytic properties were investigated using the degradation of tetracycline hydrochloride (TC) and the production of hydrogen from water splitting. Experimental results showed that the hydrogen production rate (780.5 μmol g−1 h−1) was 2.29 times that of pristine CN, and the TC removal rate (76.3%) of 1.8LDH/CN was 3.71 times that of CN. According to the detailed study of the structural, optical, and photoelectrochemical properties, a type II charge transfer mechanism was proposed to explain the improved photocatalytic performance of LDH/CN. [ABSTRACT FROM AUTHOR]

C/Ti3C2/g-C3N4 hollow microspheres (HM) were prepared by the template method to construct Ti3C2/g-C3N4 Schottky junctions on the spherical surface. The C/Ti3C2/g-C3N4 HM Schottky junctions presented excellent photocatalytic properties for producing hydrogen and decomposing organic pollutants simultaneously from wastewater without the addition of a sacrifice agent. The research revealed that the built-in electric field between g-C3N4 and Ti3C2 MXene could decrease the charge transfer resistance, leading to efficient photo charge separation, and the organic pollutant tetracycline (TC) could act as a sacrifice agent for splitting water. The H2 evolution rate of the CN-TCM-3 sample in deionized water with a sacrifice agent reached 105.4 μmol g−1 h−1, and the TC removal rate reached 100% within 120 min. The hydrogen production efficiency of CN-TCM-3 in the natural water of Slender West Lake without or with TC as a sacrifice agent was 2.3 μmol g−1 h−1 and 3.2 μmol g−1 h−1, respectively. The addition of TC improved the hydrogen production efficiency by 39%. This research indicated that the C/Ti3C2/g-C3N4 HM Schottky junctions could be a potential photocatalyst for producing hydrogen and decomposing organic pollutants in sewage simultaneously. [ABSTRACT FROM AUTHOR]

In this paper, CdS QDs@ZrO 2 –TiO 2 hollow spherical composites with double Z-scheme heterostructure modified by CdS QDs were prepared by the sol–gel method and vacuum impregnation method using polystyrene (PS) microspheres synthesized by the self-assembly technique as templates. A series of characterization results show that CdS QDs@ZrO 2 –TiO 2 composites treated by PS microspheres have the structure of hollow spheres with uniform size and orderly arrangement. Moreover, the double Z-scheme heterojunction formed between CdS QDs, ZrO 2 , and TiO 2 in the composite can optimize the charge transfer path and improve the charge separation efficiency. Results of the photodegradation and the photo-splitting water of CdS QDs@ZrO 2 –TiO 2 composites show that, compared with other systems, CdS QDs@ZrO 2 –TiO 2 composites have the highest photocatalytic degradation rate of crystal violet, and meanwhile, the photocatalytic hydrogen production rate of the composite under simulated sunlight is more than 100 times that of TiO 2. The good absorption of visible light, the successful construction of double Z-scheme heterojunction, and the unique hollow sphere structure of CdS QDs@ZrO 2 –TiO 2 composites are the key factors for enhanced photocatalytic performance. The preparation of CdS QDs@ZrO 2 –TiO 2 hollow spherical composite material with PS microspheres as templates not only expands its photoresponse range, but also optimizes the charge transfer path and improves the separation efficiency of electron–hole pairs by the construction of double Z-scheme heterojunction. [Display omitted] • CdS QDs@ZrO 2 –TiO 2 hollow spherical composite was prepared using PS microspheres as templates. • Hollow spherical CdS QDs@ZrO 2 –TiO 2 is not only uniform in spherical size, but also in neat and orderly arrangement. • Successful construction of double Z-scheme heterojunction improves charge separation efficiency. • The addition of CdS QDs expands the visible light response range. • CdS QDs@ZrO 2 –TiO 2 exhibits the highest photocatalytic activity compared with TiO 2 , @TiO 2 , and @ZrO 2 –TiO 2. [ABSTRACT FROM AUTHOR]

Constructing S-scheme heterojunction is regarded as an effective mode to motivate excellent photocatalytic performance for hydrogen generation. This paper prepares NiTiO 3 /CdIn 2 S 4 S-scheme heterostructure photocatalyst by hydrothermal method successfully. In the experiments, 20 wt% NiTiO 3 /CdIn 2 S 4 has the supreme photocatalytic activity with the H 2 generation rate of 5168.6 μmol g−1 h−1 and the apparent quantum yield (AQY) of 5.14% at 420 nm, approximately 7.7 times of pure CdIn 2 S 4. Through the phase characterization analyses, NiTiO 3 and CdIn 2 S 4 successfully compounded, with NiTiO 3 nanoparticles wrapping around CdIn 2 S 4 microspheres to form the irregular clumps. Further analyses of performance reveal the larger specific surface area, wider absorption region, faster charge transfer rate, outstanding photostability and recyclability for 20 wt% NiTiO 3 /CdIn 2 S 4 , all of which play the significant role in photocatalytic hydrogen evolution activity. Finally, a plausible S-scheme photocatalytic mechanism for NiTiO 3 /CdIn 2 S 4 is proposed. This study provides a novel and effective S-scheme photocatalyst for hydrogen generation from water splitting. • 0D/3D NiTiO 3 /CdIn 2 S 4 composite photocatalyst is prepared via hydrothermal method. • S-scheme heterojunction at the interface of NiTiO 3 and CdIn 2 S 4 is constructed. • NiTiO 3 /CdIn 2 S 4 exhibits excellent photocatalytic performance for hydrogen generation. [ABSTRACT FROM AUTHOR]

Reasonable design of heterojunction photocatalysts can effectively promote charge separation, thus improving their photocatalytic performance. Herein, a Bi2Fe4O9@ZnIn2S4 S-scheme laminated heterojunction photocatalyst with 2D/2D interface interaction is prepared via a hydrothermal–annealing–hydrothermal method. The photocatalytic hydrogen production rate of Bi2Fe4O9@ZnIn2S4 is up to 3964.26 μmol h−1 g−1, which is 12.1 times higher than that of pristine ZnIn2S4. In addition, its photocatalytic tetracycline degradation efficiency (99.9%) is also optimized. The enhanced photocatalytic performance can be attributed to the formation of S-scheme laminated heterojunctions that facilitate charge separation as well as strong 2D/2D laminated interface interactions favoring charge transfer. By combining in situ irradiation X-ray photoelectron spectroscopy with other characterization methods, the photoexcited charge transfer mechanism of S-scheme heterojunctions has been proved. Photoelectric chemical tests demonstrate the effectiveness of the S-scheme laminated heterojunction in improving the charge separation. This strategy provides a novel perspective for designing other high-efficient S-scheme laminated heterojunction photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] Construction of Z-scheme heterojunctions has been considered one superb method in promoting solar-assisted charge carrier separation of carbon-based materials to achieve efficient utilization of solar energy in hydrogen production and CO 2 reduction. One interesting concept in nanofabrication that has become trend recent years is nanoarchitectonics. A heterostructure photocatalyst constructed based on the idea of nanoarchitectonics using the combination of g-C 3 N 4 , metal and an additional semiconducting nanocomposite is investigated in this paper. Z-scheme tungsten oxide incorporated copper modified graphitic carbon nitride (WO x /Cu-g-C 3 N 4) heterostructures are fabricated via immobilization of WO x on Cu nanoparticles modified superior thin g-C 3 N 4 nanosheets. Mechano-chemical pre-reaction and a two-step high-temperature thermal polymerization process are the keys in attaining homogeneous distribution of Cu nanoparticles in g-C 3 N 4 nanosheets. The horizontal growth of homogeneously distributed WO x nanobelts on Cu modified g-C 3 N 4 (Cu-g-C 3 N 4) base via solvothermal synthesis is achieved. The photocatalytic performances of the heterostructures are evaluated through water splitting and CO 2 photoreduction measurements in full solar spectrum irradiation condition. The presence of Cu nanoparticles in the composite system improves charge transport between g-C 3 N 4 and WO x and thus enhances the photocatalytic performances (H 2 generation and CO 2 photoreduction) of the composite material, while the presence of WO x nanocomposites enhances light absorption of the composite material in the near infrared range. The synthesized heterostructure with optimized WO x to Cu-g-C 3 N 4 ratio and in case of no co-catalyst addition exhibits enhanced photocatalytic H 2 evolution (4560 μmolg-1h−1) as well as excellent CO 2 reduction rate (5.89 μmolg-1h−1 for CO generation). [ABSTRACT FROM AUTHOR]

A porous and highly dispersed Co3O4-modified ZnO@ZnS heterostructure (Co3O4–ZnO@ZnS) was developed by the simple calcination and sulfurization of the designed bimetallic ZnCo-ZIF@ZIF-8. The charge separation and transfer in this novel heterostructure were significantly improved owing to the highly dispersed Co3O4 and the porous structure. The hydrogen production rate of Co3O4–ZnO@ZnS was 1816.3 μmol g−1 h−1 with Na2S–Na2SO3 as the sacrificial agent under a Xe lamp, which was 1.5 times greater than that of ZnO@ZnS (1215.6 μmol g−1 h−1). Moreover, the photocatalytic performance of Co3O4–ZnO@ZnS was further improved by loading a Pt cocatalyst, with the hydrogen production rate reaching 3269.3 μmol g−1 h−1. This method can be used to design other effective photocatalytic heterostructures for water splitting. [ABSTRACT FROM AUTHOR]

Developing high-performance and low-cost self-supporting electrodes as pH-universal electrocatalysts for the hydrogen-evolution reaction (HER) and realizing high-quality hydrogen production at a high current density are highly desirable, but are hugely challenging. We created a self-supporting electrode with a coupled hierarchical heterostructure by simple electrodeposition followed by sulfurization. It comprised oxygen-deficient molybdenum oxide (MoO3−x) and cobalt phosphide (CoP) on nickel foam (NF), which represented a highly active pH-universal electrocatalyst for the HER at a high current density. Benefiting from a plethora of catalytic active sites, improved interfacial charge transfer, and strong electronic interaction, this type of MoO3−x@CoP/NF electrode delivered a superior catalytic performance. Overpotentials of only 100 mV, 135 mV, and 400 mV were needed to realize a high current density of 1 A cm−2 in alkaline, acid and neutral media, respectively, which were superior to those of most other well-developed materials based on non-noble metals. Our experimental work demonstrates the synergistic advantages of a MoO3−x@CoP heterostructure for improving the intrinsic catalytic performance but also paves a new path for the rational design of advanced electrodes for hydrogen generation in a wide range of pH conditions. [ABSTRACT FROM AUTHOR]

Semiconductor materials anchored with transition metal cluster are promising photocatalysts for photocatalytic hydrogen evolution. In this paper, Co, N-co-doped graphene modified thin mesoporous carbon nitride (Co-NG/TMCN) was be synthesized through electrostatic adsorption treatment. Extensive characterization was used to explore the morphology, structures and optical properties of the as-prepared photocatalysts. The 10 wt% Co-NG/TMCN exhibited the high photocatalytic hydrogen evolution rate (2949 μmol g−1) within 4 h visible light irradiation, which was about 113 times than that of the pure TMCN (26 μmol g−1). Co-NG material with excellent electrical conductivity played a major role in accelerating charge transfer from TMCN material to cobalt atomic clusters. The photocatalytic hydrogen evolution performance of Co-NG/TMCN material was effectively improved. Consequently, a feasible approach for doping transition metal clusters to enhance photocatalytic activity was provided. • The introduction of cobalt atomic clusters provided more active sites. • The synergy between Co, N-co-doped graphene and thin mesoporous carbon nitride was beneficial to the ficient separation of photogenerated electrons. • The low content cobalt atomic clusters were efficiently utilized to increase hydrogen production rate. [ABSTRACT FROM AUTHOR]

High recombination probability of photo-generated carriers restricts the characteristics improvement of semiconductor photocatalysts. The construction of heterojunction structure has become a common strategy to enhance the transport properties of carriers in catalysts. In this paper, the chain-like structure of ZnO/ZnS heterojunction was prepared by the combination of electrospinning and ion exchange. The composition and structure of ZnO/ZnS composites were studied by SEM, HRTEM, XRD, etc., and the influence of vulcanization degree on the hydrogen production of ZnO/ZnS was studied. Compared with bare ZnO, the chain-like ZnO/ZnS heterojunction shows better photocatalytic hydrogen production performance. When the Na 2 S concentration was 0.064 M, the hydrogen production of ZnO/ZnS exhibits the best performance (1140.64 μmol. g−1). Proper vulcanization treatment to construct ZnO/ZnS heterojunction structure is the key factor to boost the hydrogen generation performance. The signification enhancement of photocurrent response was observed in ZnO/ZnS composites, which also confirmed the effective charge transfer between ZnO and ZnS. In addition, the charge transfer mechanism and photocatalytic hydrogen production at the ZnO/ZnS interface was discussed by the density functional theory (DFT) calculation. It was also confirmed that the electrons distribution near the interface of ZnO/ZnS heterojunction accelerates the carrier transport of carriers, so that larger electrons and holes are involved in oxidation and reduction, thus enhancing the photocatalytic hydrogen production activity of catalysts. This work provides practical reference value for the design of new composite photocatalyst and the study of catalytic mechanism. The chain-like structure of ZnO/ZnS heterojunction was successfully synthesized through electrospinning and ion exchange methods. It is verified that the structure of ZnO/ZnS heterojunction is helpful to promote carrier transport at the interface and realize effective charge transfer. Combined with DFT theoretical calculation, through in-depth analysis of the interface structure change and charge transport performance, the electronic structure of heterojunction structure promotes the separation of photo-generated carriers and the charge transfer, and the corresponding performance of hydrogen production is also greatly improved. [Display omitted] • The chain-like structure of ZnO/ZnS was synthesized by the combination of electrospinning and ion exchange treatment. • Proper vulcanization treatment can boost the hydrogen generation performance of ZnO. • The mechanism of charge transfer and hydrogen production was discussed by DFT calculation. [ABSTRACT FROM AUTHOR]

A novel 2D/0D hybrid photocatalyst composed of porous Co x P nanosheets and Mn 0.35 Cd 0.65 S nanoparticles has been developed, and presents efficient photocatalytic H 2 evolution from water splitting. [Display omitted] • Porous Co x P nanosheets were prepared by phosphating Co(OH) 2 nanosheets. • 2D/0D Co x P/Mn 0.35 Cd 0.65 S were fabricated using a simple solution-phase method. • Co x P/Mn 0.35 Cd 0.65 S exhibited dramatically enhanced photoactivity for H 2 generation. • The behavior of photoexcited charge carriers in Co x P/Mn 0.35 Cd 0.65 S were investigated. Incorporating 2D transition-metal phosphides into visible-light-driven semiconductors is fascinating for advancing novel photocatalysts. In this paper, porous Co x P nanosheets prepared by phosphating Co(OH) 2 nanosheets are coupled with Mn 0.35 Cd 0.65 S nanoparticles for significantly boosted photocatalytic H 2 evolution performance. The optimal Co x P/Mn 0.35 Cd 0.65 S hybrids show an excellent visible-light H 2 production rate of 7188.9 μmol g−1h−1 upon visible light with an apparent quantum yield (AQY) of 18.9% at 420 nm. The H 2 production rate of the 5% Co x P/Mn 0.35 Cd 0.65 S sample is about 257 times bare CdS and even 18 times higher than pristine Mn 0.35 Cd 0.65 S. This dramatic photocatalytic H 2 generation activity is mainly ascribed to the efficient charge transfer and abundant active sites by introducing the porous Co x P nanosheets. The photocatalytic mechanism of the Co x P/Mn 0.35 Cd 0.65 S composites is investigated by the photoluminescence (PL), time-resolved photoluminescence (TRPL), electrochemical, and photoelectrochemical (PEC) tests. This work presents a viable strategy to design a 2D/0D hybrid system containing porous cobalt phosphides nanosheets and MnCdS solid solutions for noble-metal-free photocatalytic application. [ABSTRACT FROM AUTHOR]

The study of environmentally friendly semiconductor photocatalysts has important practical significance for efficient photocatalytic hydrogen evolution. In this experiment, type II heterojunction NiCo-LDH/CeO2 was prepared by in situ loading, and the NiCo-LDH/CeO2 catalyst showed good activity under simulated sunlight irradiation. Under simulated visible light irradiation, its hydrogen production rate reached 2.7 mmol h−1 g−1, which was higher than that of NiCo-LDH (0.86 mmol h−1 g−1). Through a series of characterization data, it can be concluded that the heterojunction successfully constructed by the close contact between NiCo-LDH and CeO2 accelerates the separation of photogenerated electrons and holes and can effectively inhibit the recombination of the two so that more electrons are involved in the hydrogen evolution reaction. The material has good interfacial charge transfer performance, which improves the photocatalytic performance. This work can provide an effective method for the research and development of NiCo-LDH. [ABSTRACT FROM AUTHOR]

As a research hotspot, 2D-MoS2 has been regarded as a low-cost substitute for platinum, and has fascinated researchers worldwide. Two crystalline phases of MoS2, i.e. the metallic octahedral 1T phase and semiconducting trigonal prismatic 2H phase, have been extensively analysed. In comparison to 2H-MoS2, the 1T phase exhibits enhanced and unique physicochemical properties. Designing a structure with two-dimensional mixed-phase MoS2, i.e. 1T/2H-MoS2 nanosheets, via phase engineering for effective charge separation and migration has received growing interest in the field of photocatalytic hydrogen generation. In this study, by varying the wt% of ammonium bicarbonate via a facile hydrothermal technique, a series of 1T/2H-MoS2 nanosheets have been fabricated. The presence of the corresponding elements, the electronic environment, phase purity, morphology and phase distinction were confirmed by Raman, XPS, XRD and HRTEM analyses. Additionally, the impedance data and the photocurrent density of the photocatalysts verify the efficient charge separation and transfer phenomenon. In accordance with the electrochemical measurements, the developed mixed-phase MoS2 nanosheets exhibit a six times greater current density than 2H-MoS2. Furthermore, the highest response of photocatalytic hydrogen production is observed with the photocatalyst with 79% 1T phase, which is about 17 times greater than that of pristine 2H-MoS2 due to the enrichment of active sites on both the edges and basal plane as well as the enhanced electronic conductivity due to the 1T phase. This study indicates that with the construction of a heterophase, i.e. 1T/2H-MoS2 nanosheets, the photocatalytic hydrogen evolution capability can be boosted, providing new insights regarding these materials. [ABSTRACT FROM AUTHOR]

In order to hydrogen evolution by water splitting, with appropriate design, the effective sites of the efficient heterostructured photocatalysts are boosted, and the directional transfer of the photo carriers is ensured. In this paper, we report the p-n-p heterostructured CuO/CdS/CoWO 4 nanocomposite formed with CoWO 4 deposited using microwave method on CuO/CdS prepared by combining CuO and CdS synthesized by hydrothermal method and microwave method, respectively. In the asset of an electric field formed by the S-scheme heterostructure of p-n-p CuO/CdS/CoWO 4 , efficient directional transfer of charge carriers is achieved and recombination of beneficial charge carriers is suppressed. The rate of hydrogen evolution is 457.9 μmol g−1 h−1 in the existence of CuO/CdS/CoWO 4 , which is 3.14, 11.99, 40.88 and 102.9, times as that of CuO/CdS, CdS, CuO and CoWO 4 , respectively. This study offers new perspectives on the preparation of p-n-p type rationally designed photocatalysts with improved photocatalytic efficiency and stability for hydrogen generation applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Catalysts with low cost, high efficiency, and no need for precious metal cocatalysts are the key to realizing the maximum utilization of solar energy-efficient hydrogen (H2) production. In this study, a series of graphitic carbon nitride-derived catalysts (g-C3N4/CoP@C) were successfully obtained by in situ phosphating of g-C3N4/Co-BDC. A CoP@C cocatalyst developed with Co-BDC nanosheets as precursors can accelerate the H2 generation of g-C3N4. The close interface between CoP@C and g-C3N4 increased the electron–hole separation efficiency. Moreover, the CoP@C surface carbon accelerated electron transfer and increased the light absorption range. The prepared g-C3N4/CoP@C composite material exhibited H2 production capability up to 1968 μmol g−1 (3 h), approximately 129.9 times that of g-C3N4. Therefore, the CoP@C cocatalyst is proposed as an alternative to non-precious metal cocatalysts based on the findings of the study. [ABSTRACT FROM AUTHOR]

Formic acid (FA) as a safe and promising hydrogen carrier has attracted widespread attention. The use of solid catalysts in the controllable and efficient dehydrogenation of FA is still a challenge. Here, a series of Au nanoclusters supported on rare earth metal doped ZrO2 catalysts (Au/ReZrO2 (Re = Nd, Ce and Sm)) was prepared. Doping rare earth metals in zirconia stabilizes the mixed-phase zirconia into the tetragonal phase. Meanwhile, the rare earth metal dopants can promote the formation of oxygen vacancies in zirconia, which promotes charge transfer from the support to Au and enhances the metal–support interaction on all the three catalysts. As a result, Au/ReZrO2 (Re = Nd3+, Ce3+ and Sm3+) catalysts exhibited better catalytic performance in the liberation of CO-free H2 from FA, outperforming Au supported on primary ZrO2. Structural and electronic characterization by XPS and H2-TPR further confirmed the contribution of doping rare earth metal cations in Au/ReZrO2, which can enhance the metal–support interaction and accelerate the decomposition of HCOOH into H2, thus resulting in the improvement in catalytic activity for hydrogen production from FA. [ABSTRACT FROM AUTHOR]

The construction of the heterostructures with intimate contacts and prominent sunlight absorption capacity are essential for achieving the highly effective photocatalytic H2 evolution. Here, the CdS/MoS2 heterostructures constituted by CdS nanoparticals loaded on uniform MoS2 nanoribbons were synthesized through solid‐gas reaction and hydrothermal treatments. In the as‐prepared CdS/MoS2 heterostructures, there are large‐area contact interfaces between the external highly dispersed small CdS nanoparticals and MoS2 nanoribbons. Impressively, the optimized CdS/MoS2‐8 photocatalyst delivered the highest hydrogen production rate of 91.2 μmol h−1, which is 9 times that of CdS. It demonstrates that the formation of the heterostructures could effectively promote the separation and transfer of photogenerated charge carriers due to the intimate contacts between CdS nanoparticals and MoS2 nanoribbons. This work would provide a new method to develop efficient photocatalysts for photocatalytic H2 evolution. [ABSTRACT FROM AUTHOR]

In this paper, we report a ternary Fe x Co 1−x P co-catalyst, which can greatly improve the photocatalytic performance of CdS photocatalyst for hydrogen production under visible light irradiation. The high efficiency of ternary Fe x Co 1-x P loaded CdS is mainly due to the high electrochemical activity and efficient charge transfer between Fe x Co 1-x P cocatalyst and CdS. Experimental results have shown that the substitution of Fe ions for some Co ions in CoP can change the electrochemical properties of Fe x Co 1-x P. The electrocatalytic performance of Fe x Co 1-x P and the photocatalytic activity of Fe x Co 1-x P/CdS are both dependent on the molar concentration x of Fe. When x = 0.4 the hydrogen generation rate (18.27 mmol h−1 g−1) and the quantum efficiency (50.6% at 420 nm) for 0.5 wt% Fe 0.4 Co 0.6 P/CdS photocatalyst is 5.85 times higher than that of pure CdS and 1.35 times higher than that of 0.5 wt% CoP/CdS. This new noble-metal-free Fe x Co 1-x P cocatalyst is beneficial for the solar hydrogen economy. • Ternary Fe x Co 1−x P was developed as an efficient noble-metal-free cocatalyst for PHE. • The photocatalytic activities of Fe x Co 1-x P/CdS is close to that of Pt loaded CdS. • Photocatalytic activity of Fe x Co 1-x P/CdS are dependent on the molar ratio of Fe. [ABSTRACT FROM AUTHOR]

A facile synthetic route, by using rhombic dodecahedral zeolitic imidazolate framework-8 (ZIF-8) as the structure template, is devoted to fabricating the ZnS/ZnIn2S4 hybrid heterojunction; the compact heterostructure was produced by combining the sulfurization of ZIF-8 and the in situ precipitation of ZnIn2S4 in one pot. The resulting ZnS nanoparticles of about 100 nm were uniformly dispersed in the folds of flower-like ZnIn2S4, whose structure is beneficial for charge transfer at the heterointerface. The additional quantities of ZIF-8 are varied to find an optimum ratio of the two components to obtain the best photocatalytic activity. In the photocatalytic hydrogen generation irradiated by simulated solar light, all the ZnS/ZnIn2S4 hybrid photocatalysts displayed improved hydrogen production rates compared to single ZnS or ZnIn2S4, and the best hydrogen production rate of 453.4 μmol h−1 g−1 is obtained by ZnS/ZIS-20, whose value is approximately 4 times higher than that of single ZnIn2S4. The electrochemical properties of the ZnS/ZnIn2S4 hybrid photocatalysts were measured to explore the charge transfer mode at the interface, and the band structure and enhanced photocatalytic hydrogen generation mechanism have been proposed. The excellent recycling properties of hydrogen production indicated the prospective applications of this kind of ZIF-derived metal sulfide in photocatalytic reactions. [ABSTRACT FROM AUTHOR]

This is the first report on the application of InWO4 nanospheres in the field of photocatalysis. Tungstates have excellent thermal and chemical stability; in this work, we have successfully prepared an InWO4/CdS composite catalyst. Since the CB of InWO4 is more negative than that of CdS, InWO4 can act as a cocatalyst to promote the separation and transfer of photogenerated charges, thereby suppressing the recombination of photogenerated electron–hole pairs and significantly improving the performance of the InWO4/CdS composite, and the hydrogen production rate of InWO4/CdS reached 6146.63 μmol g−1 h−1, which was about 4.21 times that of pure CdS. Especially, the InWO4/CdS composite exhibits high photocatalytic stability. In addition, these properties are well characterized by SEM, TEM, XRD, XPS, UV-vis, BET, transient photocurrent and FT-IR analyses etc., and all the results showed good consistency with the hydrogen production experiment. [ABSTRACT FROM AUTHOR]

Improving the efficiency of charge separation is an important aspect in photocatalysis. In this work, the hybrid nanostructure of α-Ni(OH)2/Zn0.5Cd0.5S has been prepared by a simple two-step method for the first time. Here, designed/constructed with α-Ni(OH)2 over Zn–Cd–S, the catalyst efficiently boosts hydrogen evolution in photocatalytic hydrogen production. With a 25% content of α-Ni(OH)2 in the ZSN25 composite under visible light (λ≥ 420 nm) irradiation, remarkable hydrogen production of 22.45 mmol g−1 h−1 has been achieved. In addition, we found that the activities could be improved by means of controlling the formation of α-Ni(OH)2 species. The reason is that the interface between α-Ni(OH)2 and Zn0.5Cd0.5S provides a fast charge transfer channel to reduce the recombination of photogenerated carrier. Also, the formation of this interface is largely related to the content of α-Ni(OH)2. The Tafel slope, EIS and PL spectra support enhanced photocatalytic energy in the α-Ni(OH)2/Zn0.5Cd0.5S charge transfer state and faster hydrogen evolution kinetics. These nanocomposites of Zn0.5Cd0.5S modified by α-Ni(OH)2 are of great significance for renewable hydrogen generation technology. [ABSTRACT FROM AUTHOR]

The solid-state Z-scheme trinary/binary heterostructures show the advantage of utilizing the high-energy photogenerated charge carriers in photocatalysis. However, the key factors controlling such Z-scheme in the binary heterostructures are still unclear. In this paper, we showed that oxygen vacancies could act as an interface electron transfer mediator to promote the direct Z-scheme charge transfer process in binary semiconductor heterostructures of CdS/ZnS. Increasing the concentration of surface oxygen vacancies of ZnO crystal can greatly enhance photocatalytic hydrogen generation of CdS/ZnO heterostructure. This was attributed to the strengthened direct Z-scheme charge transfer process in CdS/ZnO, as evidenced by steady-state/time-resolved photoluminescence spectroscopy and selective photodeposition of metal particles on the heterostructure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon coated Cu doped ZnIn 2 S 4 (Cu-ZIS@C) nanocomposites were fabricated by one-pot hydrothermal method. • The core–shell Cu-ZIS@C nanostructure possessed excellent performance in photocatalytic H 2 -evolution reaction. • The roles that carbon layer and Cu doped sites played during H 2 generation were discussed. Carbon-coated Cu doped ZnIn 2 S 4 nanostructure (Cu-ZIS@C) was synthesized through one-pot hydrothermal method. The obtained core–shell Cu-ZIS@C exhibit outstanding enhanced performance toward photocatalytic H 2 -evolution reaction. The optimized doping amount and coating could displayed a H 2 generation rate of 1455.98 μmol·g−1·h−1. The doped Cu sites could facilitate the separation of photo-generated charge carriers. Besides, the carbon layer would contribute to the improved conductivity of whole photocatalytic system and adjust the mobility of charge transfer in bulk structure. We hope this paper could offer a reference for the fabrication of core–shell nanostructure for efficient H 2 -evolution reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photo-induced carrier dynamics in Cu 2 O-modified TiO 2 studied with modulated photocurrent measurements. • Surface composition of oxides estimated using XPS. • Oxides are p-type semiconductors that effectively absorb visible light. • A mechanism of photo-induced hydrogen generation tested vs. potential dependence of charge transfer rate constant. In the present paper, photo-induced carrier dynamics and charge transfer processes on porous anodic TiO 2, modified with Cu 2 O via pulse electrodeposition, are studied with steady-state and modulated photocurrent measurements in a wide range of experimental conditions. Surface composition was estimated using XPS. The obtained oxides are p-type semiconductors that effectively absorb visible light, and rates of charge transfer and recombination are strongly dependent on synthesis conditions. A tentative mechanism of photo-induced hydrogen evolution on such materials is proposed using recent simulation results from the literature and the dependence of formal charge transfer rate constant on potential. [ABSTRACT FROM AUTHOR]

In the present work, green synthesized plasmonic copper nanostructures derived from carbon quantum dots (PCQDs) activated ZnO microarrays (MAs) based catalyst system is developed and studied for photocatalytic activity and photoelectrocatalytic water splitting. CQDs are synthesized from pharmaceutical waste and used as a reducing agent to synthesize PCQDs of an average size of 10±2 nm. PCQDs decorated ZnO (PCQDs/ZnO) MAs exhibited enhanced photocurrent density of ∼7.1 mA/cm2 at 1.23 V (vs. RHE), which is ∼11 fold to ZnO MAs alone (0.65 mA/cm2). The catalyst exhibits an ABPE of 1.07% at 0.7 V (vs. RHE), IPEC of 8.8% for 450 nm, and hydrogen production rate of 435 μmol/h. The enhanced PEC characteristics are assigned to the improved photons collection and better charge transfer for their participation in oxidation/reduction reaction. The same is well supported with DFT studies for the PCQDs/ZnO MAs catalyst for the first time. [ABSTRACT FROM AUTHOR]

A novel Co3O4 quantum dots (CQDs)/2D graphdiyne (GDY) Z‐scheme heterojunction is fabricated by cross‐coupling reaction and electrostatic self‐assembly methods. GDY with the features of 2D porous structures has not only conducted the adsorption of dye molecules but also CQDs is facile to be anchored on the surface. Additionally, the construction of Z‐scheme heterojunction is conductive to conquer the shortcomings of easy agglomeration and poor dispersion for CQDs. The maximum photocatalytic hydrogen generation rate of 1500.85 µmol h−1 g−1 is gained for 30% GDY/CQDs and display an apparent quantum efficiency of 1.37% at 475 nm, which is roughly 11‐fold and 2.8‐fold higher than the pristine GDY and CQDs, respectively. The superior photocatalytic H2 production performance would be put down to the intense synergy of Z‐scheme heterostructure and the size effect of CQDs. They dramatically enhance the separation and transport of photogenerated charge carriers. Besides, the Z‐scheme charge transfer mechanism is further verified through the results of photoluminescence. This work offers new insight into the design of GDY‐based Z‐scheme heterojunction for photocatalysis. [ABSTRACT FROM AUTHOR]

Efficient charge separation and transfer is always an important prerequisite for efficient photocatalysis. Herein, g‐C3N4/Cu/MoS2 Z‐scheme heterojunctions are successfully constructed by a two‐step calcination method, in which Cu nanoparticles are embedded as an electronic conductor between g‐C3N4 and MoS2. g‐C3N4/Cu/MoS2 composites reveal excellent photocatalytic activity. The rate of hydrogen production reaches to 970.5 µmol g−1 h−1, which is 22 and 2.63 times of that of g‐C3N4 and g‐C3N4/MoS2, respectively. Meanwhile, due to the significant enhancement of the conductivity of g‐C3N4/Cu/MoS2 and the efficient charge transfer, its electrocatalytic hydrogen evolution activity is also far superior. In addition, the electrocatalytic activity of g‐C3N4/Cu/MoS2 under light irradiation is significantly improved compared with that under dark condition. This is ascribed to the decrease of charge transfer resistance in the Z‐scheme system during light irradiation. The photochemical and electrochemical properties of g‐C3N4/Cu/MoS2 composites are compared with those of g‐C3N4/MoS2, which illustrate that the construction of g‐C3N4/Cu/MoS2 Z‐scheme heterojunction is an important factor to increase the charge transfer rate. The result provides a new idea for the realization of efficient charge transfer and the synergistic catalytic of photo and electro for water decomposition. [ABSTRACT FROM AUTHOR]

In this paper, controllable nucleation and growth of CdS nanodots on the (020)-featured WO 3 ·H 2 O nanoplates has been successfully accomplished to prepare CdS-WO 3 ·H 2 O heterojunction with high-quality interfacial contact through a slow release of Cd2+ and S2- from the gradual self-loop hydrolysis of cadmium acetate and thioacetamide. The chemical and structural characteristics of as-prepared samples before and after heat treatment are detailedly investigated by TG-DSC, XRD, Raman, XPS, FESEM and HRTEM, as well as their light absorption performance from UV-Vis DRS. The maximum average hydrogen production rate for CdS-WO 3 ·H 2 O reaches 2.15 mmol·g−1·h−1 under 300 W Xe lamp irradiation (λ > 420 nm) using lactic acid as sacrificial reagent, which is 8.27 and 2.72 times as much as CdS and CdS-WO 3 , respectively. According to band alignment, CdS-WO 3 ·H 2 O exhibits greater energy difference of Fermi level than CdS-WO 3 , and augmented photocatalytic performance should arise from efficient Z-scheme charge transfer mechanism under stronger built-in electric field, in which the conduction band electrons of WO 3 ·H 2 O and valence band holes of CdS are expected to effectively recombine at their interfacial zones, while the conduction band electrons of CdS and valence band holes of WO 3 ·H 2 O contribute to the reduction of H+ and oxidation of lactic acid. [Display omitted] • Controllable nucleation and growth of CdS on (020)-featured WO 3 ·H 2 O is achieved. • High-quality interfacial contact between CdS and WO 3 ·H 2 O has been constructed. • The max average H 2 production rate of 2.15 mmol·g−1·h−1 is 8.27 times that of CdS. • Efficient Z-scheme mechanism results in augmented photocatalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new bacterial strain Paenibacillus profundus YoMME is identified. • Electroactive biofilm of P. profundus YoMME on graphite paper is used in MEA. • Appropriate cathode and membrane are selected for MEA. • MEA is applied in BES operating in MFC or MEC mode. A novel strain of Gram-positive bacteria Paenibacillus profundus YoMME was recognized by sequencing of 16S rRNA gene and after that tested for exoelectrogenicity for the first time. It was found that at an applied potential of −0.195 V (vs. SHE) the bacteria are capable of generating electricity and forming electroactive biofilms for 3–4 days. A tendency for the decrease in double-layer capacitance and the increase in the charge transfer resistance during the maturation of the biofilm was established. The formed bioanodes were used as a part of a membrane-electrode assembly (MEA) together with a selected cathode (E-Tek) and a separator (Zirfon). The applicability of MEA with the bioanode was tested by operating a newly designed bioelectrochemical system in a microbial fuel cell (MFC) or microbial electrolysis cell (MEC) mode. A current density of 200 mA m−2 was generated by the MFC after the improvement of the cathodic reaction through facilitated air access. The Coulombic efficiency in different MFC runs ranged from 5.2 to 7.4%. It was also determined that 0.65 V applied cell voltage is appropriate for the operation of the cell in the electrolysis mode, during which a current density of 2–3 A m−2 was reached. This, along with the evolved gas on the cathode, shows that as an anodic biocatalyst P. profundus YoMME assists the electrolysis processes at a significantly lower voltage than the theoretical one (1.23 V) for water decomposition. The hydrogen production rate varied between 0.5 and 0.7 m3/m3d and the cathodic hydrogen recovery ranged from 49.5 to 61.5 %. The estimated energy efficiency based on the electricity input exceeds 100 %, which indicates that additional energy is being gained from the biotic oxidation of the available organics. [ABSTRACT FROM AUTHOR]

Designing a photocatalyst material with reduced recombination of photogenerated charges is one of the most important aspects of hydrogen generation through solar water splitting. Here, we report hydrogen generation using the TiO2/ultrathin g-C3N4 (U-g-CN) heterostructure fabricated using a unique in situ thermal exfoliation process. Multilayer g-CN is converted into U-g-CN having a high surface (∼190 m2/g) area by calcination at ∼550 °C through oxygen-induced exfoliation, which also forms a robust heterostructure with TiO2. In addition, the presence of g-CN also inhibits further growth of TiO2 nanoparticles, thereby retaining a high specific surface area. The presence of U-g-CN causes a redshift (∼0.13 eV) in the absorption edge of heterostructure compared to that of bare TiO2, which extends the light absorption capability. Addition of 40 wt. % of multilayer g-CN to TiO2 shows an enhanced H2 evolution rate, which is ∼15 times and ∼4 times higher compared to that of bare TiO2 and U-g-CN, respectively. Photoluminescence (PL) and time-resolved PL (TRPL) studies indicate a reduced recombination rate of photogenerated charge carriers with an increase in the average lifetime from 10.53 (TiO2) to 13.32 ns (TiO2/U-g-CN40). The interfacial charge transport characteristics studied through impedance spectroscopy reveal a reduced charge transfer resistance at the semiconductor–electrolyte interface, which facilitates faster charge separation due to the heterostructure formation. The band edge positions are estimated through flatband potential from the Mott–Schottky measurements and optical absorption data, indicating a type-II heterojunction. More light absorption and enhanced separation of photogenerated charges at the heterojunction interface lead to better photocatalytic H2 generation. [ABSTRACT FROM AUTHOR]

To investigate the microscopic adsorption mechanism of aluminum ion on kaolinite surfaces, we studied the adsorption of different monomeric hydroxyl aluminum on two types of neutral kaolinite (001) surfaces by means of density functional theory (DFT). This paper constructed three forms of monomeric hydrolysis models of aluminum ion, these being termed Al(OH) 2 +, Al(OH) 3 and Al(OH) 4 −. Meanwhile, the most stable adsorption configurations were selected for the analysis of the bonding, atomic population, charge transfer and density of states. Calculated results demonstrated that the three monomeric hydrolysis components are primarily adsorbed on the kaolinite (001) surface, i.e., the aluminum oxide octahedron surface. The order of adsorption stability is Al(OH) 3 > Al(OH) 2 + > Al(OH) 4 −, and the optimal adsorption sites are all located above the oxygen atoms in the hydroxyl groups which are parallel to the surface. When Al(OH) 2 + ions and Al(OH) 3 molecules are adsorbed on the kaolinite (001) surface, they depend on the interaction between the aluminum atoms in the adsorbate and the surface oxygen atoms, followed by hydrogen bonding. The adsorption of Al(OH) 4 − ion on the kaolinite (001) surface is dominated by hydrogen bonding. Following the adsorption of Al(OH) 4 − ion, the positive charge of the two kaolinite surfaces increased and the electronegativity decreased. Unlabelled Image • Al(OH) n (3- n) + (n = 2–4) are more stable adsorbed on the (001) surface. • Al(OH) 2 + and Al(OH) 3 interact via bonding between Al and surface O atoms. • The adsorption of Al(OH) 4 − ion is dominated by the H-bonding. • The interaction between Al and surface O atoms is stronger than H-bonding. [ABSTRACT FROM AUTHOR]

• Ni 2 P/MoS 2 /MWCNT was successfully synthesized by a solvothermal method followed by a thermal decomposition reaction. • (Ni 2 P,MoS 2)/MWCNT presents very good electrocatalytic activity in hydrogen evolution reaction. • The synergistic effect between the dispersion of nanoparticles of Ni 2 P/MWCNT mixed with nanosheets of MoS2/MWCNT helps to the better HER activity. In this paper, we report the synthesis and characterization of a material composed of MoS 2 nanosheets and Ni 2 P nanoparticles supported on MWCNT, employing two different routes. In the first one, MoS 2 nanosheets were supported on MWCNT followed by a thermal decomposition reaction to grow Ni 2 P nanoparticles to obtain Ni 2 P/MoS 2 /MWCNT. For the second one a mixture of MoS 2 /MWCNT, synthesized by a solvothermal method, with Ni 2 P/MWCNT, synthesized by a thermal decomposition reaction method, was prepared to obtain (Ni 2 P,MoS 2)/MWCNT. SEM and TEM images of Ni 2 P/MoS 2 /MWCNT and (Ni 2 P, MoS 2)/MWCNT, show their morphology. For Ni 2 P/MoS 2 /MWCNT, Ni 2 P grown on the surface of MoS 2 /MWCNT, and for (Ni 2 P, MoS 2)/MWCNT, the mixture was clearly identified. X-ray diffraction pattern confirms the formation of Ni 2 P on the MoS 2 /MWCNT in Ni 2 P/MoS 2 /MWCNT and (Ni 2 P, MoS 2)/MWCNT composed of Ni 2 P, MoS 2 , each one supported on MWCNT. It was observed that compared to Ni 2 P/MWCNT, MoS 2 /MWCNT, and Ni 2 P/MoS 2 /MWCNT, the mixture of (Ni 2 P, MoS 2)/MWCNT exhibits the best electrocatalytic activity for HER with a low onset overpotential of 50.42 mV (vs. RHE) and a small Tafel slope of 47 mV/dec. Also, the compound showed good stability for 50 h. The impedance spectroscopic study also confirmed that charge transfer resistance of (Ni 2 P, MoS 2)/MWCNT is lower (19.7 Ω) than Ni 2 P/MoS 2 /MWCNT (86.5 Ω). [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are a promising nanomaterial for photocatalytic applications. However, the mechanism of the photocatalytic processes remains the subject of a debate due to the complex internal structure of the CDs, comprising crystalline and molecular units embedded in an amorphous matrix, rendering the analysis of the charge and energy transfer pathways between the constituent parts very challenging. Here we propose that the photobasic effect, that is the abstraction of a proton from water upon excitation by light, facilitates the photoexcited electron transfer to the proton. We show that the controlled inclusion in CDs of a model photobase, acridine, resembling the molecular moieties found in photocatalytically active CDs, strongly increases hydrogen generation. Ultrafast spectroscopy measurements reveal proton transfer within 30 ps of the excitation. This way, we use a model system to show that the photobasic effect may be contributing to the photocatalytic H2 generation of carbon nanomaterials and suggest that it may be tuned to achieve further improvements. The study demonstrates the critical role of the understanding the dynamics of the CDs in the design of next generation photocatalysts. Efficient photocatalytic hydrogen generation relies on highly choreographed delivery of protons and electrons to the reaction site such that they arrive just in time. Here, authors show that proton transport can be controlled by light with the photobase effect to increase H2 generation rate. [ABSTRACT FROM AUTHOR]

Previous reports indicate that the catalyst CdxZn1−xS shows good activity and reliability in the process of photocatalytic hydrogen production. However, it is still a challenge to design a cost-effective catalyst to replace the traditional CdxZn1−xS. In this work, Roman broccoli Cd0.8Zn0.2S-2 was successfully prepared through reasonable adjustment and control of the amount of raw materials. In the photocatalytic hydrogen evolution test, the amount of hydrogen evolution of CZS-2 was 1.24, 1.34, 2.06, and 2.24 times that of CZS-1, CZS-3, CZS-4, and CZS-5, respectively. This is because Cd0.8Zn0.2S-2 has more excellent synergy inside. Theoretical and experimental studies show that, based on rational design, the optical and electrical properties of the CZS-2 structure have been substantially improved (based on UV–Visible diffusion and photoluminescence). The mechanism of the study shows that the photocatalytic hydrogen evolution activity of CZS-2 is effectively improved due to the favorable energy band of effective charge transfer inside CZS-2. In this work, Roman broccoli-like CZS-2 provides a new research direction for photocatalytic water decomposition. [ABSTRACT FROM AUTHOR]

We synthesized Au@WO3−x hybrids with dual plasmon resonances in visible and near-infrared (NIR) regions induced by two counterparts for enhancing photocatalytic activity. Au cores slightly influence hetero-morphology, significantly modify semiconductor plasmon, and prominently enhance H2 generation of WO3−x shells. As atom ratio of ρW:Au increases from 2 to 10, visible plasmon resonance is weakened with peak blueshifting from 540 to 490 nm, while NIR plasmon resonance strength prominently increases, and eventually average enhancement factor of photocatalytic H2 generation of the Au@WO3−x hybrids with white light illuminations increases from 1.76 to 2.85. Furthermore, the wavelength dependence of H2 generation reveals that the dominant physical mechanism of enhancing the photocatalytic activity of the hybrids is varied from excitation energy transfer to electron transfer from Au cores to WO3−x shells as ρW:Au increases. The construction of this metal-semiconductor hetero-nanostructure with dual plasmon resonances has immediate importance for the applications in solar energy conversions. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting for hydrogen generation is a significant pathway for sustainable energy conversion and production. The photocatalysts with a Z-scheme water splitting charge transfer pathway is superior due to the good separation and migration ability of photoexcited charge carriers. Herein, Co3O4/g-C3N4 photocatalysts with Z-scheme charge transfer pathway were successfully constructed by an electrostatic interaction-annealing method. The as-prepared Co3O4/g-C3N4 ultra-thin nanosheets were tested and analyzed by XRD, EA, ICP, SEM, TEM, AFM, XPS, UV-Vis DRS, PL and photoelectrochemical measurements. Moreover, the influences of fabrication parameters on performance of Co3O4/g-C3N4 catalysts were investigated, and 0.5% Co3O4/g-C3N4 exhibited the optimal activity. Based on the characterization and catalytic performance, the Z-scheme charge transfer pathway of Co3O4/g-C3N4 was established and put forward. To further improve the catalytic performance of Co3O4/g-C3N4, 0.5% Pt was added as a co-catalyst. The obtained Pt/0.5% Co3O4/g-C3N4 was recyclable and remained the original catalytic water splitting performance within 20 h. The modification of Co3O4 and Pt improved the separation and migration of e− and h+, and induced the increased hydrogen evolution rate of g-C3N4. [ABSTRACT FROM AUTHOR]

Metal-semiconductor heterostructures integrate multiply functionalities beyond those of their individual counterparts. Great efforts have been devoted to synthesize heterostructures with controlled morphologies for the applications ranging from photocatalysis to photonic nanodevices. Beyond the morphologies, the interface between two counterparts also significantly influences the performance of the heterostructures. Here, we synthesize Au/CdSe Janus nanostructures consisting of two half spheres of Au and CdSe separated by a flat and high-quality interface. Au/CdSe with other morphologies could also be prepared by adjusting the overgrowth conditions. The photocatalytic hydrogen generation of the Au/CdSe Janus nanospheres is measured to be 3.9 times higher than that of the controlled samples with CdSe half-shells overgrown on the Au nanospheres. The highly efficient charge transfer across the interface between Au and CdSe contributes to the improved photocatalytic performance. Our studies may find the applications in the design of heterostructures with highly efficient photocatalytic activity. [ABSTRACT FROM AUTHOR]