Photocatalytic production of hydrogen on Ni/NiO/KNbO3/CdS nanocomposites using visible light

Abstract

3. Enhanced activity is most likely due to effective charge separation of photogenerated electrons and holes in CdS that is achieved by electron injection into the conduction band of KNbO 3 and the reduced states of niobium (e.g., Nb(IV) and Nb(III)) are shown to contribute to enhanced reactivity in the KNbO 3 composites by mediating effective electron transfer to bound protons. We also observed that the efficient attachment of Q-size CdS and the deposition of nickel on the KNbO 3 surface increases H 2 production rates. Other factors that influence the rate of H 2 production including the nature of the electron donors and the solution pH were also determined. The Ni/NiO/KNbO 3 /CdS nanocomposite system appears to be a promising candidate for possible practical applications including the production of H 2 under visible light.

Chromium-modified Bi 4 Ti 3 O 12 photocatalyst: Application for hydrogen evolution and pollutant degradation

“…Therefore, the EDL thickness (k) of alcohol-water solution would decrease when alcohols are added to the water, and the decreased order of the k value is: isopropanol-water solution > ethanol-water solution > methanolwater solution, which is the same as their H 2 evolution rate order. The observation agrees with the previous report [53]. This explains the difference of H 2 evolution rate from different alcohol-water solutions.…”

Graphite Oxide with Different Oxygen Contents as Photocatalysts for Hydrogen and Oxygen Evolution from Water

“…A co-catalyst, serving as an electron trap, is generally required to assist water reduction for H 2 production. 60,[65][66][67] Platinum is generally used as a co-catalyst for H 2 generation. [68][69][70] Auxiliary experiments showed that in situ photodeposition of Pt did not promote the H 2 evolution rate for either catalyst.…”

Nickel-based cocatalysts for photocatalytic hydrogen production

“…In addition to sulfides and phosphides, several Ni-based oxides and hydroxides, such as NiO, NiO x and Ni(OH) 2 , are also well-known as highly active cocatalysts after being integrated with semiconductors for photocatalytic H 2 production [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77], as summarized in Table 3. For example, Chen et al showed that in situ photodeposition of NiO x on CdS could enhance its photocatalytic H 2 generation activity [63].…”

“…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]…”