Black Trumpet Mushroom-like ZnS incorporated with Cu3P: Noble metal free photocatalyst for superior photocatalytic H2 production

R Rameshbabu; P Ravi; Gina Pecchi; Eduardo J Delgado; R V Mangalaraja; M Sathish

doi:10.1016/j.jcis.2021.01.023

Black Trumpet Mushroom-like ZnS incorporated with Cu₃P: Noble metal free photocatalyst for superior photocatalytic H₂ production

J Colloid Interface Sci. 2021 May 15:590:82-93. doi: 10.1016/j.jcis.2021.01.023. Epub 2021 Jan 14.

Authors

R Rameshbabu¹, P Ravi², Gina Pecchi³, Eduardo J Delgado³, R V Mangalaraja⁴, M Sathish⁵

Affiliations

¹ Departamento Físico Química, Facultad Ciencias Químicas, Universidad de Concepción, Concepción 4030000, Chile; Millenium Nuclei on Catalytic Processes towards Sustainable Chemistry (CSC), Concepcion 4030000, Chile. Electronic address: rramachandran@udec.cl.
² Electrochemical Power Source Division, CSIR-Central Electrochemical Research Institute, Karaikudi 630 003, Tamil Nadu, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
³ Departamento Físico Química, Facultad Ciencias Químicas, Universidad de Concepción, Concepción 4030000, Chile; Millenium Nuclei on Catalytic Processes towards Sustainable Chemistry (CSC), Concepcion 4030000, Chile.
⁴ Advanced Ceramics and Nanotechnology Laboratory, Department of Materials Engineering, University of Concepcion, Concepcion 4070409, Chile.
⁵ Electrochemical Power Source Division, CSIR-Central Electrochemical Research Institute, Karaikudi 630 003, Tamil Nadu, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India. Electronic address: msathish@cecri.res.in.

PMID: 33524723
DOI: 10.1016/j.jcis.2021.01.023

Abstract

The development of the efficient photocatalysts with improved photoexcited charge separation and transfer is an essential for the effective photocatalytic H₂ generation using light energy. So far, owing to the unique properties and characteristics, the transition metal phosphides (TMPs) have been proven to be high performance co-catalysts to replace some of the classic precious metal materials in the photocatalytic water splitting. In the present work, we report a novel copper phosphide (Cu₃P) as a co-catalyst to form a well-designed fabricated photocatalyst with blacktrumpet mushroom-like ZnS semiconductor for the first time. The synthesis of Cu₃P/ZnS consists of two-step hydrothermal and ball milling methods. The physical properties of the materials so prepared were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analyses. In order to study the role of Cu₃P, electrochemical impedance spectroscopy (EIS) measurements were used to investigate the photogenerated charge properties of ZnS. The experiments of photocatalytic production of H₂ confirm that the Cu₃P co-catalysts effectively promote the separation of photogenerated charge carriers in ZnS, and consequently enhance the H₂ evolution activity. The 3% Cu₃P/ZnS sample delivers the highest catalyst activity and the consistent H₂ evolution rate is14,937 µmol h^-1 g^-1_cat, which is 10-fold boosted compared to the pristine ZnS. The stability of the catalyst was tested by reusing the used 3% Cu₃P/ZnS photocatalyst in five consecutive runs, and their respective activity in the H₂ production activity was evaluated. A possible mechanism is proposed and discussed.

Keywords: Charge carriers separation; Cu(3)P; Hole trapper; Hydrogen generation; ZnS; co-catalyst; p-n heterojunction.