Recent Advances and Future Perspectives of Lead-Free Halide Perovskites for Photocatalytic CO 2 Reduction.

It is still challenging to design and develop the state-of-the-art photocatalysts toward CO 2 photoreduction. Enormous researchers have focused on the halide perovskites in the photocatalytic field for CO 2 photoreduction, due to their excellent optical and physical properties. The toxicity of lead-based halide perovskites prevents their large-scale applications in photocatalytic fields. In consequence, lead-free halide perovskites (LFHPs) without the toxicity become the promising alternatives in the photocatalytic application for CO 2 photoreduction. In recent years, the rapid advances of LFHPs have offer new chances for the photocatalytic CO 2 reduction of LFHPs. In this review, we summarize not only the structures and properties of A 2 BX 6 , A 2 B(I)B(III)X 6 , and A 3 B 2 X 9 -type LFHPs but also their recent progresses on the photocatalytic CO 2 reduction. Furthermore, we also point out the opportunities and perspectives to research LFHPs photocatalysts for CO 2 photoreduction in the future.