The charge carrier separation and surface catalytic redox reactions are of primary importance as elementary steps in photocatalytic hydrogen evolution. In this study, both of these two processes in photocatalytic hydrogen evolution over graphitic carbon nitride(g-C_3N_4) were greatly promoted with the earth-abundant ferrites(Co,Ni)Fe_2O_4modification. Co Fe_2O_4 was further demonstrated to be a better modifier for g-C_3N_4 as compared to Ni Fe_2O_4,due to the more efficient charge carrier transfer as well as superior surface oxidative catalytic activity. When together loading Co Fe_2O_4 and reductive hydrogen production electrocatalyst Pt onto g-C_3N_4, the obtained Pt/g-C_3N_4/Co Fe_2O_4 photocatalyst achieved visible-light(λ>420 nm) hydrogen production rate 3.5 times as high as Pt/g-C_3N_4, with the apparent quantum yield reaching 3.35 % at 420 nm.
Jie ChenDaming ZhaoZhidan DiaoMiao WangShaohua Shen
Titanium dioxide(TiO_(2))has been widely investigated for photocatalytic H_(2) evolution and photoelectrochemical(PEC)water splitting since 1972.However,its wide bandgap(3.0-3.2 eV)limits the optical absorption of TiO_(2) for sufficient utilization of solar energy.Blackening TiO_(2) has been proposed as an effective strategy to enhance its solar absorption and thus the photocatalytic and PEC activities,and aroused widespread research interest.In this article,we reviewed the recent progress of black TiO_(2) for photocatalytic H_(2) evolution and PEC water splitting,along with detailed introduction to its unique structural features,optical property,charge carrier transfer property and related theoretical calculations.As summarized in this review article,black TiO_(2) could be a promising candidate for photoelectrocatalytic hydrogen generation via water splitting,and continuous efforts are deserved for improving its solar hydrogen efficiency.
