Highly conductive NiSe2 nanoparticle as a co-catalyst over TiO2 for enhanced photocatalytic hydrogen production

Designing a photocatalyst for hydrogen production is pivotal role in renewable energy technologies. Herein, the synthesis of nanosized NiSe2 particles via supercritical fluid process with the short reaction time of 30 min was reported. Then, it was used as a co-catalyst over TiO2 to improve H2 production rate. Supercritical fluid process is an effective and alternative technique for nanoparticle preparation in short time. In the presence of NiSe2, the H2 production rate of TiO2 was greatly increased thereby attained the maximum activity of 219.2 mmol/h/gcat with STH of 9% and is closer to that of Pt loaded TiO2 (9.7% for 235.5 mmol/h/gcat). The highly conductive nature of NiSe2 facilitates rapid transfer of photogenerated electrons from TiO2 to NiSe2. The detailed possible mechanism was debated and confirmed by first principles DFT calculations. This work validates short time reaction to prepare highly conductive NiSe2 as an electron sink for efficient H2 production.