Enhanced artificial nitrogen fixation efficiency induced by construction of ternary TiO/MIL-88A(Fe)/g-CN Z-scheme heterojunction.

Herein, a ternary TiO/MIL-88A(Fe)/g-CN heterojunction is successfully constructed through a facile hydrothermal strategy for enhancing solar energy harvesting and efficiency of catalytic nitrogen reduction induced by enlarged light absorption range, increasing interfacial charge transfer ability and desirable stability. Under the simulated sunlight irradiation, the N fixation experiment shows that the yield of NH reaches 1084.31 μmol/(g·h) over the TiO/MIL-88A(Fe)/g-CN photocatalyst, and the yield is significantly enhanced, which is 33.68 and 13.94 times that is higher than the pure TiO and g-CN, respectively. In a mean time, the excellent performance of the photocatalytic N fixation over the ternary TiO/MIL-88A(Fe)/g-CN is verified based on density function theory calculation and the decisive step over the composite is investigated by calculating Gibbs free energies of nitrogen reduction paths. The performance enhancement mechanism of TiO/MIL-88A(Fe)/g-CN is speculated, which indicates that the hybridized three-component system presents a desirable Z-scheme band alignment, resulting in the improvement of separation and transfer efficiency of photoinduced charge carriers. The article shows a new and high-efficiency TiO/MIL-88A(Fe)/g-CN photocatalysis for excellent nitrogen reduction ability.