B and N Codoped Cellulose-Supported Ag-/Bi-Doped Mo(S,O)<sub>3</sub> Trimetallic Sulfo-Oxide Catalyst for Photocatalytic H<sub>2</sub> Evolution Reaction and 4-Nitrophenol Reduction
Adugna Boke Abdeta, Feyisa Wedajo, Qinhan Wu, Dong–Hau Kuo, Ping Li, Hanya Zhang, Ting Huang, Jinguo Lin, Xiaoyun Chen
Abstract
Cellulose plays a significant role in designing efficient and stable cellulose-based metallic catalysts, owing to its surface functionalities. Its hydroxyl groups are used as anchor sites for the nucleation and growth of metallic nanoparticles and, as a result, improve the stability and catalytic activity. Meanwhile, cellulose is also amenable to surface modifications to be more suitable for incorporating and stabilizing metallic nanoparticles. Herein, the Ag-/Bi-doped Mo(S,O) 3 trimetallic sulfo-oxide anchored on B and N codoped cellulose (B–N–C) synthesized by a facile approach showed excellent stability and catalytic activity for PHER at 573.28 μmol/h H 2 with 25 mg of catalyst under visible light, and 92.3% of the 4-nitrophenol (4-NP) reduction was achieved within 135 min by in situ-generated protons. In addition to B and N codoping, our use of the calcination method for B–N–C preparation further increases the structural disorders and defects, which act as anchoring sites for Ag-/Bi-doped Mo(S,O) 3 nanoparticles. The Ag-/Bi-doped Mo(S,O) 3 @B–N–C surface active site also stimulates H 2 O molecule adsorption and activation kinetics and reduces the photogenerated charge carrier’s recombination rate. The Mo 4+ → Mo 6+ electron hopping transport and the O 2p and Bi 6s orbital overlap facilitate the fast electron transfer by enhancing the electron’s lifetime and photoinduced charge carrier mobility, respectively. In addition to acting as a support, B–N–C provides a highly conductive network that enhances charge transport, and the relocated electron in B–N–C activates the H 2 O molecule, which enables Ag-/Bi-doped Mo(S,O) 3 @B–N–C to have appreciable PHER performance.