Photoelectrocatalytic Surfactant Pollutant Degradation and Simultaneous Green Hydrogen Generation

Katherine Rebecca Davies; Michael G Allan; Sanjay Nagarajan; Rachel Townsend; Vijayshankar Asokan; Trystan Watson; A Ruth Godfrey; M Mercedes Maroto-Valer; Moritz F Kuehnel; Sudhagar Pitchaimuthu

doi:10.1021/acs.iecr.3c00840

Photoelectrocatalytic Surfactant Pollutant Degradation and Simultaneous Green Hydrogen Generation

Ind Eng Chem Res. 2023 Jun 2;62(45):19084-19094. doi: 10.1021/acs.iecr.3c00840. eCollection 2023 Nov 15.

Authors

Affiliations

¹ SPECIFIC, Faculty of Science and Engineering, Swansea University, Swansea SA2 8PP, Wales.
² Department of Chemistry, Faculty of Science and Engineering, Swansea University, Singleton Park, SA2 8PP Swansea, Wales.
³ Department of Chemical Engineering, University of Bath, Bath BA2 7AY, U.K.
⁴ Swansea University Medical School, Faculty of Medicine, Health and Life Science, Singleton Park, Swansea University, Swansea SA2 8PP, U.K.
⁵ Environmental Inorganic Chemistry, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, S-412 96 Göthenburg, Sweden.
⁶ Research Centre for Carbon Solutions (RCCS), Institute of Mechanical, Processing and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
⁷ Fraunhofer Institute for Wind Energy Systems IWES, Am Haupttor 4310, 06237 Leuna, Germany.

Abstract

For the first time, we demonstrate a photoelectrocatalysis technique for simultaneous surfactant pollutant degradation and green hydrogen generation using mesoporous WO₃/BiVO₄ photoanode under simulated sunlight irradiation. The materials properties such as morphology, crystallite structure, chemical environment, optical absorbance, and bandgap energy of the WO₃/BiVO₄ films are examined and discussed. We have tested the anionic type (sodium 2-naphthalenesulfonate (S2NS)) and cationic type surfactants (benzyl alkyl dimethylammonium compounds (BAC-C12)) as model pollutants. A complete removal of S2NS and BAC-C12 surfactants at 60 and 90 min, respectively, by applying 1.75 V applied potential vs RHE to the circuit, under 1 sun was achieved. An interesting competitive phenomenon for photohole utilization was observed between surfactants and adsorbed water. This led to the formation of H₂O₂ from water alongside surfactant degradation (anode) and hydrogen evolution (cathode). No byproducts were observed after the direct photohole mediated degradation of surfactants, implying its advantage over other AOPs and biological processes. In the cathode compartment, 82.51 μmol/cm² and 71.81 μmol/cm² of hydrogen gas were generated during the BAC-C12 and S2NS surfactant degradation process, respectively, at 1.75 V RHE applied potential.