A self-assembled 2D nanosheet II-type heterojunction photocatalyst for photocatalytic hydrogen evolution

The exploration of highly efficient and low-cost catalysts for photocatalytic hydrogen evolution is of great increasing interest under the dual pressure of energy shortage and environment pollution. In this work, flake-like SrCO3 was in-situ self-assembled at the surface of SrTiO3 nanosheet to fabricate a novel 2D/2D heterojunction nanocomposite catalyst with strong interaction inside these two semiconductors by a simple hydrothermal method. An accurate loading amount of SCO was responsible for the high photoactivity of 10SCO-STO-Pt, which leads to a 12.9-fold improvement of photocatalytic hydrogen evolution rate (from 0.22 to 2.83 mmol [Formula: see text][Formula: see text]) compared to that of pure STO-Pt. Meanwhile, the apparent quantum efficiency (AQE) of 10SCO-STO-Pt composite with the optimum SCO loading (10 wt.%) reached up to 16.9% under the irradiation of 313 nm light. The introduction of SCO can form a II-type heterojunction in close contact with STO, which can significantly improve the photogenerated electron transfer and reduce the recombination of photogenerated carrier in STO. As a result, the charge separation efficiency and photocatalytic activity of STO were obviously enhanced.