Metallic NiSe cocatalyst decorated g-C3N4 with enhanced photocatalytic activity

Identifying suitable noble-metal-free cocatalyst-modified photocatalysts has received tremendous attention in the nonrenewable field. Herein, non-noble metal NiSe modified g-C3N4 was produced through an environmental-friendly hydrothermal method. The NiSe/g-C3N4 photocatalyst exhibited superior photocatalytic H2 production, when the optimum mass content of NiSe was 3 wt%. The best H2-production activity could be as high as 1250 µmol·g−1·h−1, superior than that of bulk g-C3N4 by 139 times. Significantly, the 3 wt% NiSe/g-C3N4 photocatalyst showed a remarkable photocatalytic activity in oxytetracycline (OTC) and methyl orange (MO) degradation and almost completely degraded within 60 min and 5 min under the visible light irradiation, respectively. Attributed to the intimated contact between NiSe and g-C3N4, the NiSe/g-C3N4 composite shows an outstanding photocatalytic performance. Additionally, the experimental results further confirmed that the use of highly-dispersed NiSe nanodots enlarged the visible-light absorption range, boosted charge carrier mobility as well as afforded rich active sites. Importantly, DFT computation and photoelectrochemistry measurements also identified that NiSe nanodots cocatalysts accelerated the charge separation and migration, thereby implied that electron transfer pathway from g-C3N4 to NiSe. This novel technology provides a new idea for designing and studying efficient noble-metal-free cocatalyst/semiconductor compounds in the degradation of pollutant and photocatalytic H2 generation.