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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]

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]

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]

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]

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]