Fabrication of NiS modified CdS nanorod p–n junction photocatalysts with enhanced visible-light photocatalytic H2-production activity

Abstract

Production of hydrogen from photocatalytic water splitting has become an attractive research area due to the possibility of converting solar energy into green chemical energy. In this study, novel NiS nanoparticle (NP) modified CdS nanorod (NR) p-n junction photocatalysts were prepared by a simple two-step hydrothermal method. Even without the Pt co-catalyst, the as-prepared NiS NP-CdS NR samples exhibited enhanced visible-light photocatalytic activity and good stability for H2-production. The optimal NiS loading content was determined to be 5 mol%, and the corresponding H2-production rate reached 1131 μmol h(-1) g(-1), which is even higher than that of the optimized Pt-CdS NRs. It is believed that the assembly of p-type NiS NPs on the surface of n-type CdS NRs could form a large number of p-n junctions, which could effectively reduce the recombination rates of electrons and holes, thus greatly enhancing the photocatalytic activity. This work not only shows a possibility for the utilization of low cost NiS nanoparticles as a substitute for noble metals (such as Pt) in the photocatalytic H2-production but also provides a new insight into the design and fabrication of other new p-n junction photocatalysts for enhancing H2-production activity.

Nickel-based cocatalysts for photocatalytic hydrogen production

“…Ni-based sulfides, such as NiS and NiS 2 , also serve as efficient cocatalysts for photocatalytic H 2 production by coupling with proper photocatalysts [50][51][52][53][54][55][56][57][58][59][60][61]. As a p-type semiconductor, NiS has been applied in a wide range of areas due to its unique properties.…”

“…Yu and co-workers investigated the intrinsic photoactivity enhancement mechanism of NiS in combination with CdS photocatalysts [52]. By a two-step hydrothermal strategy, the composites consisting of p-type NiS nanoparticles deposited on n-type CdS nanorods were successfully fabricated with many p-n junctions generated at the interface.…”

“…In particular, Ni-based materials demonstrate excellent activity and have received much attention as H 2 -evolution cocatalysts. Many kinds of Ni-based cocatalysts, such as metallic Ni [38][39][40][41][42][43][44][45][46][47][48][49], sulfides [50][51][52][53][54][55][56][57][58][59][60][61], phosphides [62], oxides [63][64][65][66][67][68][69], hydroxides [70][71][72][73][74][75][76][77], hydrogenases [78][79][80][81], as well as molecular complexes [81][82][83][84][85][86]…”

Morphology-Controlled Synthesis of Zn<sub>x</sub>Cd<sub>1-x</sub>S Solid Solutions: An Efficient Solar Light Active Photocatalyst for the Degradation of 2,4,6-Trichlorophenol

“…Metal sulfides have been intensively studied as active photocatalysts because of their high light harvesting for promoting charge separation [8]- [12]. For example, CdS shows a high photocatalytic activity in water splitting for hydrogen production [13].…”

Effectiveness of photodecomposition of rhodamine B and malachite green upon coupled tricomponent TiO2(Anatase-Rutile)/ZnO nanocomposite

“…In response to this, materials which can remove the harmful pollutants irreversibly and eliminate them completely have been developed [1][2][3][4][5][6][7][8][9][10]. Heterogeneous photocatalysis is an emerging technique for environmental remediation, where semiconductor materials are used as photocatalysts [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. When organic pollutants are decomposed by heterogeneous catalytic reactions, the pollutant molecules are adsorbed on the surface of the catalysts, where chemical bonds are broken and formed, and eventually small organic molecules or carbonate are released as decomposed products.…”