Preparation of Cuprous Oxide Nanoparticles Coated with Aminated Cellulose for the Photocatalytic Reduction of Carbon Dioxide to Methanol

Abstract The present study utilizes microcrystalline cellulose as the raw material to prepare nanoscale cellulose crystal (NCC) particles through a hybrid method incorporating mixed acid and ultrasonic treatment. Furthermore, the NCC undergoes a surface modification through SOCl 2 chlorination and ethylenediamine (EDA) passivation, which generates graphitized aminated cellulose doped with nitrogen (NCC‐EDA). This product, due to the coordination and dispersion effects of the functional groups (e.g., amido group) on its surface, is in turn used to coat Cu 2 O nanoparticles derived from the in situ reduction of CuCl 2 ⋅2 H 2 O, which leads to a composite photocatalyst Cu 2 O/NCC‐EDA with relatively high catalytic activity. Besides the structural characterization, the present study also examines the characteristics of CH 3 OH prepared by visible‐light‐based photocatalytic reduction of CO 2 /H 2 O. The results indicate that the prepared Cu 2 O/NCC‐EDA are spherical particles with a diameter of approximately 50 nm, which are in possession of a tree‐structured rough shell capable of absorbing an increased amount of CO 2 . Under the radiation of visible light, the Cu 2 O in the prepared product is activated, yielding photoelectron–hole pairs. Driven by the nitrogen in the carrier, the formed photoelectron–hole pairs are subject to an efficient separation, and are thereby consumed by the oxidation–reduction reaction. As a result, a high activity for the photocatalyzed reduction of CO 2 is obtained.