Low-crystalline Ni(OH)2 ultrathin nanosheets upcycled from solid wastes for efficient photoconversion of low-concentration CO2

Low-crystalline ultrathin nanosheets (UNSs) hold great potential for efficient photoreduction of anthropogenic CO 2 , while developing green synthetic methodologies and elucidating the structure-performance relationship remain significant challenges. Here, via a CaO-mediated strategy , we demonstrate a facile strategy for the large-scale production of low-crystalline Ni(OH) 2 UNSs from industrial wastes. The resultant Ni(OH) 2 UNSs deliver a superior CO formation rate of 9.2 μmol h −1 with a high selectivity of 93.1 % in low-concentration CO 2 (10 %), which remarkably outperforms that of Ni(OH) 2 NSs with high crystalline. Experimental and theoretical investigations demonstrate that the boosted performance originates from the fully exposed oxygen vacancies and low-coordination Ni sites, which facilitates the separation of photogenerated charge pairs and the adsorption and activation of diluted CO 2 . This work demonstrates a sustainable strategy for the large-scale synthesis of low-crystalline layered metal hydroxides, paving new avenues for the high-value utilization of industrial wastes in mitigating climate change.