Genesis of enhanced photoactivity of CdS/Ni x nanocomposites for visible-light-driven splitting of water

Role of aliovalent cation doping in the activity of nanocrystalline CdS for visible-light-driven H2 production from water

“…A similar electron transfer mechanism has been postulated for numerous composite CdS photocatalysts such as NiS/CdS, CdS/TiO 2 , and CdS/ MoS 2 [17e19, 22]. However, we demonstrated that the dopingenhanced activity may in fact have its origin in certain bulk properties of CdS instead of the charge transfer processes mentioned above [23]. Moreover, shallow surface states or inter-bandgap charge trapping sites, which arose from the doping of an impurity, were found to be important [11,13].…”

“…The enhanced activity of modified CdS is commonly ascribed to inter-semiconductor or CdS-to-metal charge transfer steps, which occur due to the favorable band potentials of composite/hybrid photocatalysts [17e22]. However, we recently demonstrated that certain crystallographic, microstructural, and interfacial properties also control the overall photoactivity of CdS [23,24]. To examine these aspects in more detail, herein we conducted a systematic study of two different sets of CdS photocatalysts doped with a small amount (0e2 wt%) of an aliovalent cation such as Ag þ or Cr 3þ , and without using any additional noble metal cocatalyst.…”

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.…”

“…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]…”

Exploration of Zr–Metal–Organic Framework as Efficient Photocatalyst for Hydrogen Production

“…Photocatalytic hydrogen production through water splitting by using solar energy has been considered as an alternative environmentally benign way, but it is limited to develop highly active and stable photocatalysts at low cost. So far, various photocatalysts have been developed for H 2 production, for instance, metal oxide (TiO 2 [5][6][7], NiO [8], CuO [9]), metal sulfide (CdS [10], CuS [11], NiS [12], MoS [13,14]), and nitride semiconductors (C 3 N 4 ) [15][16][17][18][19][20][21][22]. Recently, Yu and coworkers have made a systematic analysis of the heterojunction photocatalysts, which provides an important reference for the subsequent photocatalytic research [23].…”