posted on 2022-01-25, 15:05authored byHaisu Wu, Tifang Miao, Qinghua Deng, Li Qian, Haixia Shi, Yun Xu, Xianliang Fu
Developing
an advanced photocatalytic water-splitting system for
hydrogen evolution reaction (HER) remains a challenge. Herein, a series
of easily available pyridine-functionalized nickel-based photocatalysts
with elaborate electronic structures were predicted by density functional
theory (DFT). The results indicated that the migration of photoinduced
electrons could be significantly improved after functionalization
of the photocatalysts, leading to a high performance for HER. Under
the optimized conditions, as high as 1613.51 μmol of H2 can be produced over 25 mg of Ni(dpi)(pys)2 (dpi = 2,2′-dipyridyl)
(pys = 2-mercaptopyridine) (PNSP 1) after irradiation
for 3 h, corresponding to a turnover number (TON) of 5470. The reaction
mechanism was further explored by experimental and DFT calculation
results. The outstanding HER performance is primarily associated with
a high photoelectron transfer rate, a weak binding energy between
the photocatalyst and hydrogen molecules, and enhanced active sites
for HER, which might benefit the reduction of the energy barrier of
HER intermediates, ultimately boosting the performance for HER. This
report on the use of DFT to predict molecular complexes with high-efficiency
catalytic properties affords significant insights for the design of
new and inexpensive photocatalysts.