Facile synthesis of Ag nanoparticles/Ti3C2Tx/polyacrylamide composite hydrogel as efficient catalyst for methylene blue and 4-nitrophenol reduction

Catalytic reduction has been regarded as one of the most efficient strategy for organic pollutants removal from aqueous solution. However, lack of efficient catalyst prevents its practical application. Herein, we design a simple and environmental friendly fabrication strategy for the 3D Ag nanoparticles/Ti3C2Tx/poly-acrylamide (Ag/MX/PAM) composite hydrogel as high efficient catalyst. In this composite hydrogel, the Ag nanoparticles, Ti3C2Tx (MXene) and polyacrylamide (PAM) act as active species, efficient electron transfer medium and high-capacity adsorbent respectively. Due to these synergistic effects for the composite hydrogel catalyst, the electron-transferring ability as well as the adsorption capacity are boosted and thus high catalytic activity achieves towards both methylene blue (MB) and 4-nitrophenol (4-NP) reduction. The superior rate constant k of 8.333 min(-1) and turnover frequency (TOF) up to 25.17 min(-1) for 4-NP reduction are realized over the 12%-Ag/MX/PAM hydrogel. Impressively, this composite hydro gel with a foam-like bulk structure can be reused easily after catalytic reaction, making it a potential catalyst for reduction of organic pollutants in industrialization. (C) 2021 The Authors. Published by Elsevier Ltd.