Fine-Tune the Electronic Structure of Copper Nanowire Networks by Heteroatom Doping Toward Enhanced Fenton-like Reaction

Abstract

To fine-tune the configuration of electrons around metal centers is critical to enhancing the activation of peroxymonosulfate (PMS) for organic decontamination in a manner similar to the Fenton-like reaction. Herein, we systematically explored the inclusion of different heteroatoms to manipulate the electronic configuration of copper nanowire (CuNW) networks toward PMS activation. Both experimental results and theoretical simulations unveiled that doping the CuNW with boron (B) to generate CuNW-B adjusted the d orbital of CuNW, optimized the electronic density of Cu active sites and endowed a proper adsorption energy of PMS, which provided the most active oxidation capacity of the materials studied. Conversely, doping with phosphorus (P) to generate CuNW-P caused evident performance decay in terms of the activation of PMS, as strong adsorption energy hindered the effective desorption of key intermediates. Accordingly, the CuNW-B boosts the Fenton-like reaction and is nearly triple and twice as effectively at degrading bisphenol A (92.5%) as CuNW-P (36.0%) and CuNW (50.5%). Thus, it was reasonably hypothesized that electronic reconstruction played an important role in improving the Fenton-like reaction. During this process, an applied potential (AP) facilitated the catalytic process by reducing Cu2+ to Cu+, which was followed by the formation of primary active species (Cu3+). Additionally, the use of a recirculating fluid flow in the reactor provided convective mass transfer, which led to more charge transfer to the structure of electrode relative to a conventional diffusion-limited batch reactor. Moreover, tests in a variety of challenging conditions demonstrated the robustness and stability of the combined CuNW-B/PMS/AP approach. This study provides an approach to finely control the electronic structure of Cu sites and is expected to guide the design of advanced Fenton-like catalysts, which could further provide a promising technology for the treatment of actual organic wastewater in a sustainable manner.