Novel p-n heterojunctions incorporating NiS1.03@C with nitrogen doped TiO2 for enhancing visible-light photocatalytic performance towards cyclohexane oxidation

Herein, p-n heterojunction photocatalysts incorporating NiS1.03@C with nitrogen doped TiO2(NiS1.03@C/N-TiO2) were synthesized via solvothermal plus annealing approach, and their photocatalytic activities towards cyclohexane oxidation were investigated. It demonstrated that NiS1.03@C/N-TiO2-3 exhibited the highest cyclohexane conversion and product selectivity of 1.86% and 90% under visible light irradiation. Moreover, it had outstanding cycling stability, maintaining 86% of the original photocatalytic conversion rate after five cycles. On the one hand, such distinctly improved photocatalytic activities were ascribed to the enhanced visible light absorption induced by N-doping TiO2. On the other hand, the p-n heterojunction and the built-in electric field could effectively facilitate the separation of electrons-holes. Besides, the presence of carbon would inhibit the agglomeration of NiS1.03 particles, promoting the adsorption of cyclohexane and desorption of oxidation products, leading to further improvement of catalytic activity. To sum up, the enhanced visible light absorption, effective charge separation and the existence of carbon all contribute to the improvement of photocatalytic performance.

Automated summary

The enhanced visible light absorption, effective charge separation, and the presence of carbon all contribute significantly to the improvement of the photocatalytic performance of NiS1.03@C/N-TiO2 heterojunction photocatalysts for cyclohexane oxidation.