In situ construction of WO3 nanoparticles decorated Bi2MoO6 microspheres for boosting photocatalytic degradation of refractory pollutants

Shijie Li; Shiwei Hu; Wei Jiang; Junlei Zhang; Kaibing Xu; Zhaohui Wang

doi:10.1016/j.jcis.2019.08.077

In situ construction of WO₃ nanoparticles decorated Bi₂MoO₆ microspheres for boosting photocatalytic degradation of refractory pollutants

J Colloid Interface Sci. 2019 Nov 15:556:335-344. doi: 10.1016/j.jcis.2019.08.077. Epub 2019 Aug 22.

Authors

Shijie Li¹, Shiwei Hu¹, Wei Jiang¹, Junlei Zhang², Kaibing Xu³, Zhaohui Wang⁴

Affiliations

¹ Key Laboratory of Key Technical Factors in Zhejiang Seafood Health Hazards, Institute of Innovation & Application, Zhejiang Ocean University, Zhoushan, Zhejiang Province 316022, China.
² Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
³ State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Research Center for Analysis and Measurement, Donghua University, Shanghai 201620, China. Electronic address: xukaibing@dhu.edu.cn.
⁴ Shanghai Key Laboratory of Urbanization and Ecological Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Institute of Eco-Chongming (IEC), Shanghai 200062, China. Electronic address: zhwang@des.ecnu.edu.cn.

PMID: 31465964
DOI: 10.1016/j.jcis.2019.08.077

Abstract

Visible-light-driven (VLD) heterojunction photocatalysts for refractory contaminant degradation have aroused huge interest because of their outstanding photocatalytic performance. From the aspect of practical application, it is important to develop a highly efficient, durable, eco-friendly and inexpensive VLD photocatalyst. Herein, we report a novel VLD WO₃/Bi₂MoO₆ heterojunction photocatalyst with remarkable photocatalytic activity, which was fabricated via an electrospinning-calcination-solvothermal route. The phase, composition, morphologies, and optical properties of WO₃/Bi₂MoO₆ heterojunctions were comprehensively characterized. The photocatalytic performance of WO₃/Bi₂MoO₆ heterojunctions was assessed by the removal of rhodamine (RhB) and tetracycline hydrochloride (TC) under visible light (VL). WO₃/Bi₂MoO₆ heterojunctions displayed superior photocatalytic activities compared to Bi₂MoO₆, WO₃, or the mechanical mixture of WO₃ and Bi₂MoO₆. In particular, the heterojunction material (0.4WB, theoretical molar ratio of WO₃/Bi₂MoO₆ is 0.4/1.0) exhibited the best degradation efficiency (100%) and mineralization rate (52.3%) in 90 min, both of which exceeded the observed rates for Bi₂MoO₆ by 5.3 and 6.4 times, respectively. Moreover, 0.4WB showed a good durability in eight runs. The optimized photocatalytic property of WO₃/Bi₂MoO₆ can be attributed to enhanced VL absorption and reduced recombination efficiency of carriers owing to the synergistic effects between Bi₂MoO₆ and WO₃. The necessity of direct contact between WO₃/Bi₂MoO₆ and contaminants was experimentally verified. The study on photocatalytic mechanism demonstrates that superoxide free radicals (O₂^-) and photo-generated hole (h⁺) are dominantly responsible for the pollutant degradation, as demonstrated by the trapping experiments and electron spin resonance (ESR) analysis. Therefore, the WO₃/Bi₂MoO₆ heterojunction holds huge potential to be utilized as a durable and highly active photocatalyst for wastewater treatment.

Keywords: Electrospinning; Heterojunction; Visible-light photocatalysis; WO(3)/Bi(2)MoO(6).