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In situ assembly of ZnIn 2 S 4 nanosheets on the surface of nickel-based Hofmann-type coordination polymer (Ni-Ni HCP) nanoplates and Mo-ion doping was first reported. The hydrogen production rate of the prepared Ni–Ni HCP/Mo–ZIS sample under visible-light irradiation was 10 times that of pure ZIS. [Display omitted] Solar energy-assisted hydrogen production technology is an essential tool for exploring hydrogen energy. To date, semiconductors have been used as the primary photocatalyst to generate hydrogen via photocatalytic water splitting. However, the high photogenerated electron–hole recombination rate of semiconductor photocatalysts results in a low hydrogen production rate. Herein, the synergistic effect of Mo-ion doping and the incorporation of Ni-based Hofmann-type coordination polymer (Ni–Ni HCP) on the photocatalytic performance of ZnIn 2 S 4 (ZIS) is investigated. The hydrogen production rate of the prepared in-situ Mo doped ZnIn 2 S 4 wrapped Ni-Ni HCP (Ni–Ni HCP/Mo–ZIS) sample under visible-light irradiation is 26.7 mmol g−1h−1, which is 10 times that of pure ZIS. Hydrogen production rate test, microscopic characterization, and density functional theory calculation confirm that the proposed dual modulation approach (combined ion doping and heterogeneous structure construction) could effectively increase the photocatalytic efficiency of ZIS. The stability of prepared samples is also examined by four-cycle photocatalytic hydrogen production tests. The proposed integrated method opens a new route for advancing renewable energy technology towards a sustainable future. [ABSTRACT FROM AUTHOR]

A novel CoMn 2 O 4 -ZnIn 2 S 4 (CMO-ZIS) hollow microcubes composite catalyst with p-n heterojunction was constructed. Surprisingly, the 10% CoMn 2 O 4 -ZnIn 2 S 4 (CMO-ZIS-10) exhibits a PHE rate of up to 11.04 mmol h−1 g−1, approximately 3.6 times higher than pure ZnIn 2 S 4. [Display omitted] • The as-prepared CoMn 2 O 4 -ZnIn 2 S 4 hollow structure can not only increase the absorption efficiency of sunlight, but also provide more active sites. • The novel p-n scheme heterojunction improve the photoinduced carriers separate and transfer. • The CoMn 2 O 4 -ZnIn 2 S 4 photocatalyst displayed an improved photocatalytic hydrogen evolution rate, which is about 3.6 times that of pure ZIS. Semiconductor photocatalytic hydrogen evolution (PHE) is used to convert solar energy to hydrogen energy. Therefore, a low-cost, effective, and dependable photocatalyst could be a viable solution to environmental and energy crises. However, performing energy-conversion reactions by preparing photocatalysts with suitable photoabsorption and effective charge separation is challenging. Herein, a novel CoMn 2 O 4 -ZnIn 2 S 4 (CMO-ZIS) hollow microcube composite catalyst with a p-n heterojunction is constructed, in which ZnIn 2 S 4 nanosheets are grown in situ on the surfaces of CoMn 2 O 4 hollow microcubes. Surprisingly, 10% CoMn 2 O 4 -ZnIn 2 S 4 (CMO-ZIS-10) exhibits a PHE rate of up to 11.04 mmol h−1 g−1, which is approximately 3.6 times higher than that of pure ZnIn 2 S 4. In addition, to maintain the excellent visible light absorption efficiency of ZnIn 2 S 4 nanosheets, the close-contact heterogeneous interface of CMO-ZIS enables easy separation and transfer of the carriers. Furthermore, the hollow structure increases the absorption efficiency of sunlight and provides more active sites, thus increasing the reactivity of photocatalyst. In this paper, we report a workable approach for building heterojunction photocatalysts powered by water splitting. [ABSTRACT FROM AUTHOR]

The shortage of fossil energy has become a growing global concern. It is particularly important to make full use of the infinite solar energy resources, and transform them into sustainable and clean energy. The development of hydrogen energy has become a feasible solution to solve the energy shortage problem. The preparation of photocatalysts featuring efficient charge transfer channels and high hydrogen production activity provides a pathway for the development of hydrogen energy. In this paper, we report for the first time the direct assembly of 2D ZnIn 2 S 4 (ZIS) nanosheets on the surface of CoTiO 3 (CTO). The synthesized CoTiO 3 /ZnIn 2 S 4 (CTO/ZIS) photocatalyst features a direct Z-scheme charge transfer channel, which enhances the separation rate of photogenerated carriers, and accelerates the photocatalytic H 2 evolution (PHE) rate. Without the assistance of any co-catalyst, the PHE rate of prepared CoTiO 3 /ZnIn 2 S 4 was as high as 5.21 mmol g−1 h−1. Moreover, the H 2 evolution rate of CoTiO 3 /ZnIn 2 S 4 almost did not decrease significantly after four consecutive 4 h cycles. This investigation provides a valuable approach for the exploitation of novel and efficient Z-scheme photocatalysts in the application of solar energy to hydrogen energy conversion. Using the Z-scheme CoTiO 3 /ZnIn 2 S 4 photocatalyst, water is decomposed under visible light irradiation to produce large amounts of H 2. The conversion of solar energy to hydrogen energy is realized. [Display omitted] • This is the first report of in situ assembly of ZnIn 2 S 4 nanosheets on CoTiO 3 surface. • The as-prepared CoTiO 3 /ZnIn 2 S 4 showed a new Z-scheme heterojunction. • The CoTiO 3 /ZnIn 2 S 4 heterojunction displayed an improved photocatalytic hydrogen evolution rate. [ABSTRACT FROM AUTHOR]