Amorphization-Induced Cation Exchange in Indium Oxide Nanosheets for CO 2 -to-Ethanol Conversion.

Cation exchange (CE) in metal oxides under mild conditions remains an imperative yet challenging goal to tailor their composition and enable practical applications. Herein, we first develop an amorphization-induced strategy to achieve room-temperature CE for universally synthesizing single-atom doped In 2 O 3 nanosheets (NSs). Density functional theory (DFT) calculations elucidate that the abundant coordination-unsaturated sites present in a-In 2 O 3 NSs are instrumental in surmounting the energy barriers of CE reactions. Empirically, a-In 2 O 3 NSs as the host materials successfully undergo exchange with unary cations (Cu 2+ , Co 2+ , Mn 2+ , Ni 2+ ), binary cations (Co 2+ Mn 2+ , Co 2+ Ni 2+ , Mn 2+ Ni 2+ ), and ternary cations (Co 2+ Mn 2+ Ni 2+ ). Impressively, high-loading single-atom doped (over 10 atom %) In 2 O 3 NSs were obtained. Additionally, Cu/a-In 2 O 3 NSs exhibit an excellent ethanol yield (798.7 μmol g -1 h -1 ) with a high selectivity of 99.5% for the CO 2 photoreduction. This work offers a new approach to induce CE reactions in metal oxides under mild conditions and constructs scalable single-atom doped catalysts for critical applications.