Photocatalytic Reduction of Carbon Dioxide by Hydrous Hydrazine over Au–Cu Alloy Nanoparticles Supported on SrTiO₃/TiO₂ Coaxial Nanotube Arrays

Efficient photocatalytic conversion of CO 2 into CO and hydrocarbons by hydrous hydrazine (N 2 H 4 ⋅H 2 O) is achieved on SrTiO 3 /TiO 2 coaxial nanotube arrays loaded with Au–Cu bimetallic alloy nanoparticles. The synergetic catalytic effect by the Au–Cu alloy nanoparticles and the fast electron‐transfer in SrTiO 3 /TiO 2 coaxial nanoarchitecture are the main reasons for the efficiency, while N 2 H 4 ⋅H 2 O as the H source and electron donor provides a reducing atmosphere to protect the surface Cu atoms from oxidation, therefore maintaining the alloying effect which is the basis for the high photocatalytic activity and stability. This approach opens a feasible route to enhance the photocatalytic efficiency, which also benefits the development of photocatalysts and co‐catalysts.