Electroless plating Ni-P cocatalyst decorated g-C_3N_4 with enhanced photocatalytic water splitting for H_2 generation

摘要

This work reports the nickel-phosphorus (Ni-P) cocatalyst decorated graphitic C3N4 (g-C3N4/Ni-P for photocatalytic water splitting to H-2 generation. The g-C3N /Ni-P composite is prepared through two steps, first step is thermal decomposition of urea to produce g-C3N4 and the second step is electroless plating to coast Ni-P on the g-C3N4 surface, resulting in the noticeable increase of the photocatalytic activity of g-C3N4. Among these as - prepared samples reported in this work, the highest photocatalytic activity is detected at 3 wt% (g-C3N4/Ni-P-3%), in which H-2 production rate is 1051 mu mol g(-1) h(-1). However, higher than 3 wt% Pt modification the g-C3N4 generates only 841 mu mol g(-1) h(-1) of H-2, and almost no generation of H-2 by pure g-C3N4 has been determined. Based on photoluminescence and photocurrent measurements, a photocatalytic mechanism for pure g-C3N4 and g-C 3N4/Ni-P-3% has been suggested, that is, the loading of Ni-P NPs accelerates the separation of photogenerated e (-)-h(+) pairs and relaying photogenrated e(-) via Ni-P particles to react with H2O, and thus improves photocatalytic performance of g-C3N4 for water splitting into H-2 generation.