Improved visible-light photoactivity of Pt/g-C3N4 nanosheets for solar fuel production via pretreated boric acid modification
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In this work, the photocatalytic activities of g-C3N4 nanosheets for CO2 conversion and H2 production were obviously promoted by modifying an appropriate amount of Pt as the photoelectron-acceptor and co-catalyst. The optimized 0.5Pt–CN displayed ~ 2-times higher photocatalytic activities for both CO2 reduction and H2 production than those of bare CN nanosheets. Importantly, the photocatalytic activities for solar fuel production of Pt–g-C3N4 nanosheets can be further enhanced by pretreating a suitable amount of boric acid modification on g-C3N4 nanosheets. Compared to 0.5Pt–CN and bare CN, the optimized 0.5Pt–5B–CN (5% boric acid in molar ratios) displayed ~ 2- and 9-times enhancement for reducing CO2 to CO, as well as CH4 while ~ 2- and 10-times enhancement for H2 production, respectively. By means of the steady-state surface photovoltage spectra, fluorescence spectra and fluorescence spectra related to the produced ·OH amount, the exceptional photoactivities were comprehensively attributed to the boric acid-assisted high dispersion of Pt on g-C3N4 nanosheet which enhances the charge separation and improves the co-catalytic activity. This pretreated boric acid modification strategy is also applicable for other noble metals like Ag and Au. This work provides a new strategy on developing an efficient g-C3N4-based photocatalyst for solar fuel production.
KeywordsPt/g-C3N4 nanosheet Pretreated boric acid modification Charge separation Visible-light photocatalysis Solar fuel production
This work was supported by the National Natural Science Foundation of China (U1401245, 21706044, 21501052 and 91622119), the China Postdoctoral Science Foundation (2015M570304, 2017M621316) and Special Funding for Postdoctoral of Heilongjiang Province (LBH-TZ0619).