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Establishing efficient charge‐transfer channels that provide sufficient active sites to enhance the activity of photocatalysts remains a challenging problem. In this work, n‐type CoP2 semiconductors as one of the main active components for efficient hydrogen evolution are obtained from bulk P‐CoV‐LDH. The emergence of CoP2 semiconductors not only enriches the active sites but also carries a large amount of negatively charged P, which can act as a base to seize more protons, thereby accelerating the precipitation of hydrogen. To achieve oriented control of carrier migration, the ZnxCd1−xS solid solution is effectively combined with P‐CoV‐LDH for the first time to synthesize a highly efficient and stable S‐scheme heterojunction photocatalyst. The best P‐CoV‐LDH/ZnxCd1−xS 30% composite has a hydrogen evolution rate of 1244.3 µmol without noble metal additives, which is 6.4 times more than ZnxCd1−xS. S‐scheme heterojunctions exhibit remarkable photocarrier separation efficiency and low interfacial migration resistance. [ABSTRACT FROM AUTHOR]

Summary: By means of hydrothermal vulcanization method, NiFe‐PBA with a three‐dimensional cubic structure is used as a precursor, and NiFe‐PBA is converted to NiFe‐PBA‐S while maintaining its original three‐dimensional cubic structure. NiFe‐PBA‐S/ZnCdS was successfully synthesized by physical synthesis. Compared with monomeric NiFe‐PBA‐S and ZnCdS, the hydrogen evolution rate of NiFe‐PBA‐S/ZnCdS composite catalyst is significantly higher. In particular, NiFe‐PBA‐S/ZnCdS not only showed a high hydrogen evolution rate of 20 060 μmol g−1 h−1 but also exhibited good cycling durability. For the ZnCdS growth system, the unique three‐dimensional (3D) structure of NiFe‐PBA‐S acts as an excellent growth site for the ZnCdS nanoparticles, preventing their aggregation and extending the ZnCdS reaction zone. In addition, the S‐scheme heterojunction inhibits the recombination of electron‐hole pairs. The 3D spatial structure and S‐scheme heterojunction configuration allow for more efficient and easy charge transfer, which substantially improves the separation and transfer of electrons. This research expands upon the notion of designing photocatalysts for efficient hydrogen evolution. Highlights: NiFe‐PBA‐S and ZnCdS have S‐scheme charge transfer.The unique structure of NiFe‐PBA‐S is conducive to the dispersion of ZnCdS.The performance of 10% NiFe‐PBA‐S/ZnCdS photocatalytic hydrogen production is significantly improved, and it has high reusability. [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]

Hydrogen production from water splitting is considered as a brand-new and promising way to convert solar energy into recyclable chemical energy. Herein, a core–shell-shaped structure which consisted of Mn0.05Cd0.95S nanorods and flowerlike NiAl-LDH microsphere was constructed via a simple hydrothermal method. The constructed Mn0.05Cd0.95S/ NiAl-LDH core–shell-shaped structure shows superior photocatalytic H2 evolution. The highest photocatalytic H2 evolution rate of the composite is 7.5 mmol g−1 h−1, which is 17 and 6 times higher than those of NiAl-LDH and Mn0.05Cd0.95S respectively. The core–shell like structure is beneficial for the H2 production reaction because NiAl-LDH flowerlike microsphere can provide large surface for the anchoring of Mn0.05Cd0.95S nanorods, which can enhance the interaction between these two materials. A series of characterizations including XRD, FT-IR, SEM, TEM, BET, XPS, UV−vis DRS, etc., were conducted and studied to analyze the reason for the enhanced photocatalytic hydrogen evolution activity. The results of XPS show that an interaction between NiAl-LDH and Mn0.05Cd0.95S has been occurred. The interaction between these two materials is presented through the transfer of electrons, which can be demonstrated by the results of XPS. And, it is found that the rational designed structure can accelerate the transfer of electrons and this is the reason for the enhanced photocatalytic evolution performance. A core-shell like structure consisted of Mn0.05Cd0.95S nanorods and NiAl-LDH nanoflower like sphere was designed rationally via a simple method. The NiAl-LDH nanoflower like sphere with some wrinkles on its surface can provide more areas to contact with Mn0.05Cd0.95S nanorods, which can is beneficial for the interaction between these two materials and accelerate the transfer of electrons. [ABSTRACT FROM AUTHOR]

Research on cheap co-catalysts to increase hydrogen evolution and improve catalyst stability is an important developmental direction in the field of photocatalytic hydrogen release. In this work, Mo15S19/CdS nanocomposites were synthesized via a facile multistep synthesis method. On account of the larger specific surface area, more active sites and more favorable photogenic carrier separation of the composite photocatalyst, the 5%-Mo15S19/CdS obtained the highest hydrogen production capacity. The rate reached 142.9 μmol h−1 (10 mg), which is 8.4 times that of the pristine CdS nanorods. The introduction of Mo15S19 can reduce the surface resistance and improve the transportation of photogenerated electrons on the surface of CdS, resulting in a significant reduction in the recombination rate of the photogenerated electrons, thereby promoting the photocatalytic hydrogen production performance of CdS. This work not only provides an effective co-catalyst to improve the rate of photocatalytic water splitting of CdS, but also provides a reference for the development of novel high efficiency catalysts. [ABSTRACT FROM AUTHOR]

An efficient and stable NiTiO3/MoS2−P photocatalyst was prepared with means of hydrothermal and calcination. After optimization, the maximum hydrogen production of the composite sample reached 337.82 μmol in 5 h. After phosphating NiTiO3 nanorods and MoS2, the original structure of 3D nanorods and 2D nanosheets was maintained, which forms a tight interface between the two materials. In addition, the heterojunction established in the NiTiO3/MoS2−P composite material resulted in good separation of electrons and holes, thereby improving the photocatalytic efficiency under light conditions. Efficient charge transfer efficiency was also confirmed in photoelectrochemical experiments. Furthermore, photoluminescence spectroscopy experiments have confirmed that the formation of heterojunction between the two semiconductors increases the carrier lifetime of the composite catalyst and has efficient separation efficiency. SEM, TEM, BET, UV‐vis DRS and other series of characterization methods were used to characterize the prepared materials. [ABSTRACT FROM AUTHOR]

Graphdiyne (GD), a novel two‐dimension carbon hybrid material, due to its unique and excellent properties, has been widely concerned since this innovative material was successfully synthesized by Prof. Yuliang Li in 2010. Traditionally, its synthesis method is growing graphdiyne on copper foils or foam copper as a base catalytic material to deliver copper ions (Cu2+) under pyridine conditions. Here, an innovative progress for graphdiyne preparation approach of using Cu+ ion as a catalytic material is reported and its application in extending to the photocatalytic water‐splitting to produce hydrogen in situ as well. In detail, by means of cuprous iodide used as a catalyst‐carrier to grow a graphdiyne in a pyridine solution of monomeric hexynylbenzene and such CuI‐graphdiyne composite catalyst is directly applied to photocatalytic hydrogen production in situ. Meanwhile, the hydrogen production of GD and CuI are 29.42 μmol/5 h and 156.49 μmol/5 h, respectively. In particular, the composite catalyst GD‐CuI exhibits an optimum photo‐catalytic hydrogen production activity (465.95 μmol/5 h) which is 15.8 times and 3.0 times that of pure GD and CuI respectively. This rational design, one‐step construction of GD‐CuI, successfully enhances photo‐catalytic hydrogen evolution activity. The deeper characterization study results such as TEM, SEM, XPS, XRD, UV‐vis DRS, Transient photocurrent and FT‐IR etc. have been well researched and the results of which are in good agreement with each other. [ABSTRACT FROM AUTHOR]

In this work, C@Zn x Cd 1-x S/Co 3 O 4 catalyst which with high hydrogen production activity was prepared and the catalyst was characterized by SEM, TEM, XRD, XPS, Uv–vis DRS characterization. After two-step modification, the light absorption intensity of C@Zn x Cd 1-x S and C@Zn x Cd 1-x S/Co 3 O 4 showed an increasing trend compared with pure Zn x Cd 1-x S, such phenomenon was beneficial to the visible light absorption and utilization of photocatalyst. In addition, Mott-Schottky proved that Zn x Cd 1-x S catalyst formed p-n heterojunction with Co 3 O 4 nanoparticles, which further demonstrated that the modification of Zn x Cd 1-x S by Co 3 O 4 was successful. And the hydrogen production of C@Zn x Cd 1-x S/Co 3 O 4 (30%) (1405.1 μmol) was 6.9 times that of pure Zn x Cd 1-x S. The improvement of photocatalytic performance can be attributed to that carbon particles accelerate the storage and transfer of electrons, and the formation of p-n heterojunction between Co 3 O 4 and Zn x Cd 1-x S promotes the separation of photogenerated carriers effectively. In this study, the introduction of amorphous carbon and Co 3 O 4 promoted the transfer and separation of electrons and holes greatly, thereby inhibited the recombination of carriers and provided the favorable conditions for the preparation of highly efficient and stable photocatalysts. • Novel C@Zn x Cd 1-x S/Co 3 O 4 composite is prepared. • The effective separation and transport of photogenerated charge is obtained. • p-n heterostructure effectively promotes carrier separation. [ABSTRACT FROM AUTHOR]

In this work, the rational design of amorphous NixB as a co-catalyst for the modification of ZnxCd1−xS was achieved. First, NixB was prepared by the redox method and ZnxCd1−xS was synthesized by the hydrothermal method. Then, the electrostatic self-assembly method was used to complete the coupling of NixB and ZnxCd1−xS. The experimental results of H2 production showed that when the mass ratio (wt%) of NixB in NixB/ZnxCd1−xS was 7 wt%, it had the highest activity, and the hydrogen production could reach 1521 μmol under irradiation with light for 5 h. The hydrogen production activity of the composite catalyst was 4.75 times higher than that of pure ZnxCd1−xS. The improvement in the photocatalytic activity can be attributed to the following aspects: (i) UV-vis DRS showed that the addition of NixB increased the absorption of visible light; (ii) the PL, TRPL, IT, EIS and LSV experiments further proved that the composite catalyst had excellent photoelectrochemical properties; (iii) the zeta potential results indicated that the electrostatic attraction between NixB and ZnxCd1−xS provided favorable conditions for the rapid transfer of electrons. This work shows that amorphous NixB has a prominent effect on the modification of ZnxCd1−xS, which provides more ways for the study of photocatalytic H2 evolution. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) nanoflower can inhibit lamellar stacking to expose more edge active sites, showing larger surface areas and shorter electron transport paths. In this work, with the help of polyvinylpyrrolidone (PVP) morphology modifier, three-dimensional (3D) nanoflower MoS x was synthesized by hydrothermal method. The ZIF-9(Co)-derived CoP nanoparticles adhere to MoS x by means of a three-dimensional flower structure to form a MoS x /CoP photocatalyst. The 3D nano-flower of MoS x with layered structure can be observed in TEM images. This unique layered structure not only effectively inhibits the mutual stacking of MoS x nanosheets but also play a good role in dispersing CoP nanoparticles. In addition, the unsaturated Mo and S atoms exposed to the edge also promote the edge activity of sulfur, playing the role of active sites. Meanwhile, the CoP can also serve as active sites, which P as base sites can trap the positively charged protons. During the catalytic reaction, the Co atom and the P atom act as the double proton adsorption site in the CoP [P(δ−)-Co(δ+)], which could accelerate the water cracking. Besides, PL, EIS and Mott-Schottky show that MoS x and CoP play a synergistic role during the reaction, and the contact between them opens up a channel for accelerating the electron transfer to avoid electron aggregation. Thus, the MoS x /CoP is exhibited lower overpotential, larger apparent current density and higher conductivity. The MoS x /CoP-20 shows the highest photocatalytic activity of 8730 μmol g−1 h−1 under visible light irradiation. In this work, MoS x /CoP has excellent photocatalytic activity, which provides a reference for future energy innovation. • MoS x nanoflower structure can effectively shorten the electron transfer path. • MoS x layered structure exposes more active sites. • CoP as a dual proton adsorption site to accelerate the decomposition of water. • The interface between CoP and MoS x forms channel to accelerate electron transfer. [ABSTRACT FROM AUTHOR]

In this work, a novel photocatalyst Ni(OH)2&Ce(OH)3@P-CdS was synthesized successfully by phosphorization of CdS and in situ loading of Ni(OH)2&Ce(OH)3 on the surface of P-CdS. It was found that the introduction of the element P can expand the absorption range of light, prolong the lifetime of the photoinduced carriers of CdS and enhance photocatalytic hydrogen evolution activity. Importantly, we found that Ni(OH)2&Ce(OH)3 can play the role of storing holes, which can efficiently inhibit the recombination of photoinduced electron–hole pairs, thus enhancing hydrogen evolution activity, the hydrogen evolution activity of Ni(OH)2&Ce(OH)3@P-CdS is 11.36 mmol g−1 h−1, which is 4.2 times greater than that of P-CdS. A series of characterization methods, including XRD, SEM, TEM, XPS, BET, UV-vis DRS, PL and TRPL spectroscopy and electrochemical methods (IT, LSV, EIS, MS), were performed, aimed at studying the behavior of Ni(OH)2&Ce(OH)3@P-CdS. The BET result showed that coupling Ni(OH)2&Ce(OH)3 with P-CdS can enhance the specific surface area of the compound catalyst. Also, the UV-vis DRS results showed that the introduction of Ni(OH)2&Ce(OH)3 can expand the absorption range of light. Importantly, photoluminescence spectroscopy (PL) showed that the recombination of photoinduced electron–hole pairs was hindered greatly after adding Ni(OH)2&Ce(OH)3 into the system. [ABSTRACT FROM AUTHOR]

Bimetallic solid solutions have attracted much attention in the field of photocatalysis due to their excellent photocatalytic properties. Here, Zn 0.7 Cd 0.3 S solid solution with two morphologies was prepared by typical solvent-thermal method. The co-existence of 1D rod-like Zn 0.7 Cd 0.3 S and 2D sheet-like Zn 0.7 Cd 0.3 S can be found in SEM and TEM diagrams. This special structure can provide a larger specific surface area for exposing more active sites and expanding optical contact surface, which is favorable for boosting photocatalytic water-splitting reaction. In addition, a p-n junction formed by the interface contact between NiWO 4 and Zn 0.7 Cd 0.3 S effectively promotes the transfer of interfacial charges through the built-in electric field, and thus recombination of the electron-hole pairs is greatly inhibited. The highest photocatalytic H 2 production rate in the Na 2 S/Na 2 SO 3 system is 15.95 mmol h−1 g−1, which is 3.16 times higher than the bare Zn 0.7 Cd 0.3 S. Meanwhile, Mott-Schottky curves further confirmed the Zn 0.7 Cd 0.3 S and NiWO 4 suitable conduction band and valence band position, forming a more effective thermodynamic charge transfer path. This work provides for the first time 2D/1D structure of Zn 0.7 Cd 0.3 S and highlights the more efficient photocatalytic hydrogen evolution performance of the p-n junction in Zn 0.7 Cd 0.3 S/NiWO 4. [ABSTRACT FROM AUTHOR]

Ni/ZnxCd1−xS composite photocatalyst was successfully synthesized by hydrothermal method and in situ photodeposition method, and certain hydrogen evolution results were obtained in acidic, neutral and alkaline sacrificial reagents. Among them, hydrogen evolution amount reached 11.993 mmol h−1 g−1 in alkaline Na2S/Na2SO3 solution. According to SEM, TEM and Mapping, two solid solutions of ZnxCd1−xS were formed under specific reaction conditions, which provided a large specific surface area and increased the contact area between metal Ni and ZnxCd1−xS, leading to more electron transfer. The UV–Vis diffuse reflectance spectra indicates that, due to the interface interaction between Ni and ZnxCd1−xS, the photodeposition of Ni leads to the reduction of the band gap of the photocatalyst, the expansion of visible light absorption range, and the generation of more photogenerated electrons. The excellent electron transport ability of Ni leads to the rapid separation of electron–hole pairs, inhibits the recombination of electron–hole pairs, and greatly improves the photocatalytic activity. This work describes the effective synergistic effect of Ni/ZnxCd1−xS photocatalysis, showing good hydrogen evolution effect, and emphasizes the excellent electronic conductivity without noble metal synergistic catalyst. [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]

On account of on the dominant performance of Ni 2 P, rGO and g-C 3 N 4 itself, with a view to conquer the disadvantages of Ni 2 P, rGO and g-C 3 N 4 its own, the g-C 3 N 4 /rGO/Ni 2 P is successfully designed and prepared by a simple hydrothermal reaction, which is used in dye-sensitized system for high-efficient photocatalytic H 2 evolution. The rGO is adhered to the outside appearance of the g-C 3 N 4 nanosheets and fish-scale shape Ni 2 P is anchored on the surface of rGO and g-C 3 N 4. The above three forms a synergistic effect. The maximum amount of H 2 evolution reaches about 266 μmol for 5 h over the g-C 3 N 4 /rGO/Ni 2 P photocatalyst when the content of rGO is 8%, which is 10.6 times higher than g-C 3 N 4. Synergy between the above three materials is certified by some characterizations and the results of which are consistent with each other. In addition, the possible mechanism of photocatalytic hydrogen production is proposed. • The photocatalytic performance of the [g-C 3 N 4 /rGO/Ni 2 P] was reported for the first time. • The composites exhibited greatly enhanced photocatalytic hydrogen evolution rate. • Well dispersion of Ni 2 P and intimate interface between g-C 3 N 4 and rGO nanosheets contributed to the high activity. [ABSTRACT FROM AUTHOR]

The separation and transfer of photoelectrons is a crucial factor in the process of photocatalysis. Herein, we successfully designed and prepared WP as a cocatalyst, modified the g-C3N4(CN)/CdS heterojunction structure, achieved the effective separation and directional transfer of photoelectrons, and also efficient photocatalytic hydrogen evolution. In addition, the as-prepared WP–CN/CdS composite photocatalyst not only prominently improved the separation and pre-assigned transfer of photogenerated electrons, but also had abundant surface active sites, which greatly improved the photocatalytic performance of the catalyst; namely, the highest photocatalytic activity of WP–CN/CdS was achieved at 5% WP content and the highest hydrogen production rate could reach 18 238.89 μmol h−1 g−1, which is about 12.49 times that of pure CdS. The detailed characterization studies with SEM, TEM, XRD, XPS, DRS, UV–vis, BET, transient photocurrent, FT-IR etc. effectively supported the abovementioned results, and all the characterization results were in good agreement with each other. Moreover, a possible mechanism of the photocatalytic reaction in the WP–CN/CdS system is proposed. [ABSTRACT FROM AUTHOR]

Ni2P nanoparticle contained no precious metal as co‐catalyst to touch up CdS nanorods coupling with graphitic C3N4 for H2 evolution was synthesized successfully by in‐situ fabrication approach. The preparative Ni2P‐CdS/g‐C3N4 composite catalyst exerts remarkable hydrogen production activity and exhibit good photostability in 20 hour cycles. The hydrogen evolution rate is 9.9 times as high as that of pure CdS. Morphological characterization, optical results and electrochemical test proved that special CdS/g‐C3N4 enhanced the transfer of electrons on CdS and g‐C3N4, loading Ni2P co‐catalyst further increased the synergistic effect in photocatalytic properties. Several characterization results such as transmission electron microscopy (TEM), X‐ray diffraction (XRD), The Ultraviolet–visible spectroscopy diffuse reflectance spectroscopy (UV‐vis DRS), Photoluminescence (PL) and nitrogen adsorption‐desorption isotherms (BET) etc. indicate that the Ni2P nanoparticles loaded on the CdS/g‐C3N4 exposed more active sites and facilitated the efficiency of photogenic electron‐hole pairs separation. Optimistically, these results were good consistent with each other. This considerable performance probablely attribute to the special conduction band (CB) and valence band (VB) of CdS and g‐C3N4 which form a heterojuction and the introduction of Ni2P as cocatalyst further extract photogenerated electrons that lower the over potential of H+ redution. Ni2P nanoparticle contained no precious metal as co‐catalyst to touch up CdS nanorods coupling with graphitic C3N4 for H2 evolution was synthesized successfully by in‐situ fabrication approach. The composite catalyst exhibits efficient hydrogen evolution and good photostability in 20 hour cycles in the visible light irradiation decomposition water system. The hydrogen evolution rate is 9.9 times as high as that of pure CdS [ABSTRACT FROM AUTHOR]

Graphdiyne (GDY) is a new two-dimensional layered structure of carbon isomers composed of sp and sp2 hybridized carbon atoms, which has attracted much attention in many fields because of its unique energy band structure, stability and high carrier mobility. However, GDY has been rarely reported in the study of photocatalytic hydrogen precipitation. In this work, graphdiyne-CuI (GDY-CuI) was successfully prepared by cross-coupling method using Cu salt (CuI) instead of Cu foil. Based on the modulation of the energy band structure and redox ability of the photocatalyst, a typical S-scheme heterojunction was constructed by introducing MoO 2 through in situ sonication and stirring, and the composite catalyst 10%GC/Mo exhibited step-like electron transfer and strong redox ability. Under the action of internal electric field, this unique heterojunction can induce rapid electron transfer in a directional manner, which effectively promotes the separation of photogenerated electrons and holes in MoO 2 , thus improving the photocatalytic hydrogen evolution performance. The photocatalytic hydrogen evolution rate of the composite photocatalyst 10%GC/Mo was 32.8 μmol (8 mg of catalyst acted for 5 h), which was 32 times that of primitive MoO 2. The introduction of GDY-CuI accelerates the charge separation and transfer rate, prolongs the lifetime of photogenerated carriers, and reduces the reaction overpotential. This work provides a reference for the application of the novel two-dimensional photocatalytic materials GDY and GDY-CuI in the field of photocatalysis. • The cleverly constructed double S-scheme heterojunction ensures a strong redox capacity. • Reasonable band matching between semiconductors shortens charge transfer paths. • The lower hydrogen evolution overpotential ensures the photocatalytic hydrogen evolution reaction of the composite catalyst. • The performance of 10%GC/Mo photocatalytic hydrogen evolution is significantly improved, and it has high reusability. [ABSTRACT FROM AUTHOR]

• Cu 3 P@CoP composite photocatalyst was obtained by phosphating Cu-MOFs@ZIF-9(Co) at low temperature. • Cu 3 P@CoP composite photocatalyst has a self-supporting hierarchical 3D structure. • Construction of p-n-type heterojunction Cu-P@Co-P interface. • The built-in electric field of the p-n type heterojunction provides a fast electron transmission channel. In this study, we developed a novel in situ growth scheme to construct the Cu-MOFs@ZIF-9(Co) core-shell precursor material. The Cu-MOFs@ZIF-9(Co) core-shell precursor was treated by low-temperature phosphorization to obtain a Cu 3 P@CoP composite catalyst with a self-supporting structure. Cu 3 P@CoP composite catalyst not only had a hierarchical structure, but also built a p-n heterojunction at the interface. The unique structure and composition of Cu 3 P@CoP could promote charge migration and provide large surface area and rich active sites to drive water photolysis. In addition, by controlling the degree of phosphation of Cu-MOFs@ZIF-9(Co) material and adjusting the ratio of Cu and Co, it was found that the maximum hydrogen-producing activity of the composite photocatalyst reached 469.95 μmol (9399 μmol h−1 g−1), and it had a very excellent cycle stability. The results of photoelectrochemical and fluorescence tests showed that the proper conduction and valence band positions of Cu 3 P and CoP formed a more effective path way for the thermodynamic charge transfer. The construction of p-n type heterojunction provided a fast electron transfer channel in the Cu-P@Co-P interface. The formed special structrue and the existence of the bult-in electric filed in the p-n heterojunction made the photogenerated carriers in the composite have more effective separation and lower recombination rate, which significantly enhanced H 2 production activity. At the same time, our work will provide a new strategy for the rational design of efficient catalysts of MOFs derivatives and a new direction for the design of transition metal phosphide photocatalysts. [ABSTRACT FROM AUTHOR]

The NiCoB/Mn 0.05 Cd 0.95 S composite catalyst is designed to further improve the hydrogen production performance of Mn 0.05 Cd 0.95 S solid solution. Amorphous NiCoB nanoalloy is used as the co-catalyst to provide more reaction sites for the Mn 0.05 Cd 0.95 S solid solution. [Display omitted] • There was close contact between the NiCoB and Mn 0.05 Cd 0.95 S. • The NiCoB increases the absorption of visible light. • The NiCoB can effectively transmit electrons from the Mn 0.05 Cd 0.95 S conduction band because it has the minimum resistance. A low-cost and effective method was crucial to enhance the photocatalytic H 2 evolution performance of the catalysts. In this work, the amorphous NiCoB nanoalloy was prepared by simple redox method. Mn 0.05 Cd 0.95 S solid solution was modified by the NiCoB nanoalloy as co-catalyst. The catalytic evaluate experiments showed that the maximum H 2 evolution activity of the NiCoB/Mn 0.05 Cd 0.95 S after five hours of light exposure was 523 μmol, much higher than that of pure Mn 0.05 Cd 0.95 S. Enhanced H 2 evolution performances of NiCoB/Mn 0.05 Cd 0.95 S should be caused to the following aspects. The Zeta potential and TEM results showed that the NiCoB and the Mn 0.05 Cd 0.95 S were in close contact. The UV–vis DRS indicated that the composite catalyst had excellent light absorption capacity. The efficient charge separation capability of the composite catalyst were demonstrated by the PL, TRPL and EIS. Obviously, the NiCoB nanoalloy played an important role in the high photocatalytic performance of the NiCoB/Mn 0.05 Cd 0.95 S. This work will provide a new reference for the study of photocatalytic H 2 evolution of the Mn 0.05 Cd 0.95 S solid solution. [ABSTRACT FROM AUTHOR]

CoSe2, as a kind of co-catalyst, would replace noble metals element to dope pure CdS. The CoSe2/CdS photocatalyst could be synthesized by simple physical mixing. With the introduction of CoSe2, especially 30% CoSe2/CdS, hydrogen production would be about 500 μmol within 5 h, five times that of pure CdS under the same conditions. The CoSe2/CdS photocatalyst could bear four cycles of hydrogen evolution and sustain the hydrogen production, with a minor decrease. In other words, the electron transition velocity would surge along with the introduction of CoSe2 particles. The CoSe2 could be deemed as the predator and exit of electrons to inspire the detachment of the hole-electron pairs and relieve the recombination of the hole-electron pairs. [ABSTRACT FROM AUTHOR]

Accelerating the electron transport efficiency is the key to improving photocatalytic performance. In this work, a hydrothermal strategy was developed to anchor the granular ZnCdS onto amorphous CoSP and form the S-scheme heterojunction photocatalyst ZnCdS/CoSP with the formation of special S-P and Co-S bonds to improve the hydrogen production performance and stability of photocatalysts. The results show that the hydrothermally synthesized materials have 193, 8.2 and 1.13 times higher photocatalytic hydrogen production rates than those of CoSP, ZnCdS and physically synthesized ZnCdS/CoSP, respectively. The ZnCdS/CoSP photocatalysts have been demonstrated by X-ray photoelectron spectroscopy, hydrogen production experiments and some other characterizations that the S-scheme heterojunction constructed by ZnCdS/CoSP can improve the interfacial interaction of ZnCdS-CoSP. The S-P bond and Co-S bond constructed by both posses penetrating electron channels, which can effectively promote the interfacial charge transfer. The strategies of constructing S-scheme heterojunctions and S-P bonds and Co-S bonds provide new ideas for improving the separation efficiency of photogenerated carriers and optimizing the interfacial engineering photocatalyst projects. [Display omitted] • S-scheme heterojunction endows significantly improved charge transfer. • The enhanced activity was attributed to the efficient interfacial bonding for efficient charge separation and transfer. • ZnCdS/CoSP shows ultrahigh photocatalytic H 2 evolution performance and photostability. [ABSTRACT FROM AUTHOR]

A novel ZnCdS/NiCoP S-scheme heterojunction was obtained by a facile hydrothermal method for highly photocatalytic H 2 generation, and the cubic NiCoP was derived from a Prussian blue analog by phosphatization. The cubic NiCoP serves as an excellent substrate for hosting homogeneous ZnCdS nanoparticles and forms stable ZnCdS/NiCoP S-scheme heterojunctions with it. The optimal ZnCdS/NiCoP-3% composite photocatalyst of 10 mg achieved after 5h excellent photocatalytic H 2 of 582.98 μmol along with a high AQY of 7.93% (450 nm), which is 4.16 and 500 times higher than the pristine ZnCdS and NiCoP photocatalysts, respectively. This work will help to design noble metal-free and efficient S-scheme heterojunction photocatalysts, providing a new perspective to explore photochemically catalyzed hydrogen precipitation. [Display omitted] • Constructed the novel S-scheme ZnCdS/NiCoP heterojunction photocatalyst. • Introduced Prussian blue analog to solar-to-chemical energy conversion. • Cubic-like NiCoP highly dispersed the seriously aggregated ZnCdS nanoparticles. • Greatly accelerated the spatial separation and migration of charge carriers. • Largely improved the photocatalytic hydrogen evolution performance. This study used a facile hydrothermal technique to obtain a novel ZnCdS/NiCoP S-scheme heterojunction for highly photocatalytic H 2 generation, Notably, phosphatization was used to derive the cubic NiCoP from a Prussian blue analog ZnCdS nanoparticles are simple to disperse on the surface because NiCoP has a cubic characteristic, which easily transfers interface charges, and consequently accelerates surface reaction kinetics. Furthermore, the ZnCdS/NiCoP-3% composite exhibited the highest photocatalytic H 2 generation performance of 582.98 µmol with an apparent quantum yield (AQY) of 7.93% at 450 nm in the lactic acid aqueous solution, which is approximately 4.16 and 500-fold higher than that of the pure ZnCdS and NiCoP, respectively. Additionally, outstanding photostability was achieved after 20h of the four cycling experiments. Consequently, the peachy photocatalytic hydrogen evolution can be imputed for establishing S-scheme heterojunction, maintaining doughty redox capacity and achieving spatial separation of charges, thereby vastly restraining the fast recombination of photoexcitation. Furthermore, the photoluminescence (PL) spectroscopy and hydroxyl radical (OH) capture experiments further proved the S-scheme mechanism. Therefore, this study provides a neoteric perspective establishing S-scheme photocatalytic systems for solar energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Direct assembly of 2D/3D microstructures facilitates the exposure of the active site. • The wide range of ZnCr LDHs facilitates the absorption of light energy. • S-scheme heterojunction accelerates the separation of photogenerated charge. • ZZC-25 has very high hydrogen evolution activity compared with a single catalyst. Zinc-chromium layered double hydroxides (ZnCr LDHs) occupy longer wavelength of the absorption range due to the existence of trivalent Cr ion, which is beneficial to capture more photons. However, the catalytic performance of single ZnCr LDHs is limited by the feeble dynamics. Herein, the 2D/3D S-scheme heterojunction ZnCr LDHs/ZIF-67 was coupled together by moderate electrostatic self-assembly to block the recombination of photogenerated charges on single ZnCr LDHs. Thanks to the successful formation of S-scheme heterojunction, the prepared ZZC-25 heterojunction presents a high hydrogen evolution of about 3.0 mmol g−1 h−1, which is 308.34 times and 4.82 times higher than that of ZnCr LDHs and ZIF-67, respectively. The results demonstrate that the incorporation of an S-scheme heterojunction serves as an effective strategy to enhance the photocatalytic performance of a single wide spectrum semiconductor. The present study offers experimental guidance for the efficient separation of photo-generated carriers in LDHs-based wide-spectrum semiconductors. [ABSTRACT FROM AUTHOR]

Accelerating the separation and migration efficiency of photogenerated charge carriers and creating abundant active sites are the keys to the excellent H 2 production performance of photocatalysts. In this work, two strategies, the construction of S-scheme heterojunction and the introduction of active P species, were carried out based on polyhedral Ni-MOF-74 and layered CoAl LDH, in order to accelerate the separation and migration of electron-hole pairs as well as create rich active sites for more improved photocatalytic H 2 evolution performance. First, a delicate Ni-MOF-74/CoAl LDH S-scheme heterojunction was constructed, and then Ni-MOF-74/CoAl LDH was converted to CoAlP/Ni 2 P S-scheme heterojunction. That is, the active P species was introduced based on the presence of S-scheme heterojunction. More importantly, Ni-MOF-74/CoAl LDH S-scheme heterojunction photocatalyst exhibits visible improvement in H 2 generation rate in comparison with single Ni-MOF-74 and CoAl LDH, which is attributed to the formation of S-scheme heterojunction undoubtedly. Further, CoAlP/Ni 2 P S-scheme heterojunction shows more improved H 2 production performance than Ni-MOF-74/CoAl LDH, suggesting that P-modification is a high-efficiency means for enriching surface active sites and implementing the conversion of S-scheme heterojunction to S-scheme heterojunction. • An S-scheme heterojunction composed of CoAlP and Ni 2 P was formed. • P-modification is an high-efficiency means for enriching surface active sites. • The recombination of photoinduced electron-hole pairs was inhibited. • Highly improved photocatalytic hydrogen evolution activity was obtained. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Well-designed functional Ni nanoparticles modified ZIF-67(Co) derived Co 3 O 4 /CdS p-n heterojunction is synthesized. • Defect-induced [Co 3 O 4 /CdS/Ni] photocatalyst exhibits efficient hydrogen production. • A series of characterization studies is well mutual corroboration with each other. Abstract Well-designed functional noble metal-free Ni nanoparticles as co-catalyst to modified ZIF-67(Co) derived Co 3 O 4 framework materials/CdS p-n heterojunction photocatalyst for efficient hydrogen evolution was successfully synthesized via photo-assisted in-situ method. The obtained noble metal-free defect-induced [Co 3 O 4 (3 wt%)/CdS/Ni] mesoporous photocatalyst exhibit excellent photocatalytic activity, namely, the maximum amount of hydrogen evolution reaches about 512 μmol for 5 h over the [Co 3 O 4 (3 wt%)/CdS/Ni] photocatalyst under visible light irradiation, which is 14.2 times higher than that of the pure CdS. Deeper further research confirms that the red shift of absorption band edge, the enhancement of light absorption intensity, the short fluorescence lifetime (2.61 ns), the faster electron injection rate (K ET = 1.17 × 108 s−1), the larger efficiency of electron injection (η inj = 30.6%), the high photocurrent response and the smaller R 1 (22.3 Ω) and R 2 (16,207 Ω) together accelerate the efficient spatial charges separation and transfer. The deeper characterization study results such as TEM, SEM, XPS, XRD, UV–vis DRS, Transient photocurrent and FT-IR etc. shown that the Ni nanoparticles modified on the Co 3 O 4 /CdS provided the more active sites and improved the efficiency of photo-generated charge separation, the results of which were in good agreement with each other. [ABSTRACT FROM AUTHOR]

Graphical abstract Ni 2 P and g-C 3 N 4 occupied the binding sites on UiO-66 and provide the more active sites. Abstract Stable and efficient photocatalyst is the key important research goals up to now. On account of the dominant performance of Ni 2 P, g-C 3 N 4 (graphitized carbonitride) and UiO-66 (Universitetet i Oslo) themselves, an orderly-designed assemble of g-C 3 N 4 /UiO-66/Ni 2 P is successfully designed and assembled with capability of high-efficient dye-sensitized photocatalytic H 2 evolution. The electron transport routes are successfully adjusted and the hydrogen evolution is greatly improved. It exhibits synergistic effect on highly efficient photocatalytic hydrogen production. The maximum amount of hydrogen evolution reaches about 200 μmol for 5 h over the g-C 3 N 4 /UiO-66/Ni 2 P photocatalyst under the 5 W LED white light at 420 nm. The H 2 evolution rate is 12 times high than over g-C 3 N 4. Such synergistically increased effect in photocatalytic properties is certified by related characterization results such as TEM, SEM, XPS, XRD, UV–vis DRS, Transient photocurrent and FT-IR etc. The above studies show that the Ni 2 P nanoparticles modified on the g-C 3 N 4 /UiO-66 provides the more active sites and improves the efficiency of photo-generated charge separation. In addition, the possible mechanism of photocatalytic hydrogen production is proposed. [ABSTRACT FROM AUTHOR]

The spatial separation of photogenerated electrons and holes in ZIF-67@NiAl LDH semiconductor with strong redox capability was realized by three factors including the built-in electric field, band bending and coulomb attraction. Morphology regulation and heterojunction construction can effectively improve the utilization rate of photogenerated carriers and promote the catalytic activity. The introduction of P atom further promoted the application of photogenerated electrons in photocatalytic reaction of reducing water. [Display omitted] • An S-scheme heterojunction composed of ZIF-67 and NiAl LDH was formed. • The migration rate of photocarriers is accelerated by the introduction of phosphorus. • The recombination of photoinduced electron-hole pairs was inhibited. • Highly improved photocatalytic hydrogen evolution activity was obtained. Reasonable control of the interface of semiconductor materials is one of the potential strategies to develop efficient solar photocatalysts for hydrogen production. In the S-scheme heterojunction, the valid electrons and holes are preserved and the meaningless photocarriers are reorganized. Using the strategy of band structure matching and morphology regulation, we tightly coupled ZIF-67 with NiAl LDH by electrostatic self-assembly method, and constructed ZIF-67@NiAl LDH composite catalyst with S-scheme heterojunction structure. In addition to improving the interfacial charge transfer efficiency of catalyst, the design of S-scheme charge transfer path can enhance the redox capacity of catalyst to a certain extent. The design of two-dimensional/one-dimensional spatial structure increases the contact interface between ZIF-67 and NiAl LDH, which is conducive to the production of active sites. In addition, the introduction of P accelerates the carrier separation efficiency. Finally, phosphating ZIF-67@NiAl LDH catalyst showed excellent hydrogen production activity (2.99 mmol g-1h−1) with a 5 W LED as light source and eosin as a photosensitizer. This work provides experimental support and theoretical basis for the design of photocatalysts for efficient catalytic hydrogen evolution involving sacrificial reagents. [ABSTRACT FROM AUTHOR]