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 In2O3 nanosheets (NSs). Density functional theory (DFT) calculations elucidate that the abundant coordination-unsaturated sites present in a-In2O3 NSs are instrumental in surmounting the energy barriers of CE reactions. Empirically, a-In2O3 NSs as the host materials successfully undergo exchange with unary cations (Cu2+, Co2+, Mn2+, Ni2+), binary cations (Co2+Mn2+, Co2+Ni2+, Mn2+Ni2+), and ternary cations (Co2+Mn2+Ni2+). Impressively, high-loading single-atom doped (over 10 atom %) In2O3 NSs were obtained. Additionally, Cu/a-In2O3 NSs exhibit an excellent ethanol yield (798.7 μmol g-1 h-1) with a high selectivity of 99.5% for the CO2 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.
Keywords: CO2 photoreduction; amorphous structure; cation exchange; ethanol formation; metal oxides; single-atom doped catalysts.