CuInSe2 Quantum Dots Embedded in Bi2WO6 Nanosheets for Electrocatalytic Nitrogen Reduction

For hundreds of years, ammonia has been an important raw material for industrial production worldwide. At present, the electrocatalytic nitrogen reduction reaction (NRR) has become a very attractive and promising method for NH₃ synthesis. But due to the high bond energy and strong dipole moment of the N≡N bond in nitrogen gas, it is extremely difficult to decompose. At normal temperature and pressure, the reaction kinetics of the NRR is still relatively slow. Herein, CuInSe₂ quantum dots (CuInSe₂-QDs) are highly dispersed on the surface of Bi₂WO₆ nanosheets to form p–n heterojunctions, which can effectively increase the reaction rate of NRR. As a result, CuInSe₂ QDs-Bi₂WO₆ exhibit a high yield rate of 36.1 μg h^–1 mg_cat^–1 and NH₃ Faradaic efficiency of 9.3%, which is superior to the pristine Bi₂WO₆ (9.1 μg h^–1 mg_cat^–1 5.1%) under neutral solution. CuInSe₂ QDs-Bi₂WO₆ also shows good electrochemical stability. This work provides a promising solution for designing NRR catalysts and may also open up paths for the preparation of intrinsic heterostructures.