Fig. 1

Schematics of the strategy for fabricating Bi_xSn_1-x nano-alloy catalysts and the Bi–Sn phase diagram. a A flow chart showing the experimental procedures. b, c The Bi–Sn nano-alloys are used as catalysts for electrochemical reduction of CO₂ (c) and the annealed Bi–Sn nano-alloys are further used as catalysts for photocatalysis degradation of an organic model dye (b). d Bi–Sn binary alloy phase diagram (adapted from ref. ⁸) with the compositions used in this study indicated. L: liquid phase; S: solid phase