Carbothermal synthesis of biochar-supported metallic silver for enhanced photocatalytic removal of methylene blue and antimicrobial efficacy

Jun Shi; Jun Wang; Lebin Liang; Zhen Xu; Yu Chen; Shi Chen; Mengmeng Xu; Xiaozhi Wang; Shengsen Wang

doi:10.1016/j.jhazmat.2020.123382

Carbothermal synthesis of biochar-supported metallic silver for enhanced photocatalytic removal of methylene blue and antimicrobial efficacy

J Hazard Mater. 2021 Jan 5:401:123382. doi: 10.1016/j.jhazmat.2020.123382. Epub 2020 Jul 6.

Authors

Jun Shi¹, Jun Wang², Lebin Liang¹, Zhen Xu¹, Yu Chen¹, Shi Chen¹, Mengmeng Xu¹, Xiaozhi Wang³, Shengsen Wang⁴

Affiliations

¹ College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China.
² College of Resources and Environment, Shandong Agricultural University, Taian, 271018, PR China.
³ College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, PR China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225127, Jiangsu, PR China.
⁴ College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, PR China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225127, Jiangsu, PR China. Electronic address: wangss@yzu.edu.cn.

PMID: 32763685
DOI: 10.1016/j.jhazmat.2020.123382

Abstract

Pinewood biochar (PBC)-supported metallic silver (Ag^o) was prepared via a one-step carbothermal reduction route (AgH) or a wet-chemistry reduction method (AgW). XRD and SEM confirmed Ag^o was soldered on PBC matrix. Low methylene blue (MB) sorption was observed for unsupported Ag^o nanoparticles (AgNP), AgH and AgW. Under ultraviolet (UV) light irradiation, net MB degradation by AgH (15.88 g kg^-1) was higher than that of AgW (12.50 g kg^-1) and AgNP (10.27 g kg^-1). TOC removal percentages after degradation corresponded largely to reduction of MB concentrations in solution, indicating MB was dominantly mineralized. Electron paramagnetic resonance (EPR) revealed that MB was degraded by reactive oxygen species (ROS) such as hydroxyl radical (OH), superoxide radical (O₂-) and singlet oxygen (¹O₂). The scavenging experiments further suggested that OH scavengers suppressed MB degradation to a greater extent than other quenchers. Compared to AgW, AgH possessed greater abundance of persistent free radicals, which enhance ROS generation. PBC could also improve separation of electron-hole (e^--h⁺) pairs and enhance electron transfer ascribing to favorable carbon structure. Besides, PBC-Ag^o maintained good antimicrobial efficacy over E.coli DH5α. This work presented a facile carbothermal route to prepare Ag^o-based photocatalysts for dye removal and microbial inhibition in industrial wastewater.

Keywords: Biochar; Degradation; Free radicals; Industrial waste; Methylene blue.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents
Charcoal
Methylene Blue*
Silver*

Substances

Anti-Bacterial Agents
biochar
Charcoal
Silver
Methylene Blue