Recent Developments in the Use of Heterogeneous Semiconductor Photocatalyst Based Materials for a Visible-Light-Induced Water-Splitting System—A Brief Review

Prabhakarn Arunachalam,Rajabathar Jothi Ramalingam,Mabrook S Amer,Mohamed A Ghanem,Keiji Nagai,Abdullah M Al-Mayouf

doi:10.3390/catal11020160

Abstract

Visible-light-driven photoelectrochemical (PEC) and photocatalytic water splitting systems featuring heterogeneous semiconductor photocatalysts (oxynitrides, oxysulfides, organophotocatalysts) signify an environmentally friendly and promising approach for the manufacturing of renewable hydrogen fuel. Semiconducting electrode materials as the main constituents in the PEC water splitting system have substantial effects on the device’s solar-to-hydrogen (STH) conversion efficiency. Given the complication of the photocatalysis and photoelectrolysis methods, it is indispensable to include the different electrocatalytic materials for advancing visible-light-driven water splitting, considered a difficult challenge. Heterogeneous semiconductor-based materials with narrower bandgaps (2.5 to 1.9 eV), equivalent to the theoretical STH efficiencies ranging from 9.3% to 20.9%, are recognized as new types of photoabsorbents to engage as photoelectrodes for PEC water oxidation and have fascinated much consideration. Herein, we spotlight mainly on heterogenous semiconductor-based photoanode materials for PEC water splitting. Different heterogeneous photocatalysts based materials are emphasized in different groups, such as oxynitrides, oxysulfides, and organic solids. Lastly, the design approach and future developments regarding heterogeneous photocatalysts oxide electrodes for PEC applications and photocatalytic applications are also discussed.

Highlights

The accessibility of an economical, clean, and copious energy source is one of the foremost challenges for humankind in the 21st century
Methodologies benefit from permitting the comparatively homogeneous wrapping of CoPi over the (Oxy)nitride surface of the photoanodes. These results show that the incorporation of CoPi over (Oxy)nitride has been an efficient route to enhance the PEC current gain via the PEC water oxidation reaction
A series of heterogenous photocatalyst materials have been examined for PEC water splitting reaction

Summary

Introduction

The accessibility of an economical, clean, and copious energy source is one of the foremost challenges for humankind in the 21st century. The PEC water splitting system is one of the promising methods to examine the electron transfer process in producing oxygen (O2 ) in water oxidation reaction to use solar energy [17,18,19,20,21] In this regard, several oxide-based electrode materials have been investigated [22,23,24,25,26,27,28,29,30,31,32,33,34,35]. In recent years, (Oxy)nitrides-based electrode materials have gained much consideration They must be investigated in numerous ways, namely morphological features, co-doping strategies, defect induced features, surface activation, co-catalyst loading, etc. NTs (Ag/TiON), (b) LSV plots under the irradiation of TiO2 , TiON and Ag/TiON, (c) the IPCE spectra of the samples, and (d) the IPCE of Ag/TiON electrodes under externally applied bias [134]

Oxysulfide Based Photocatalyst

Other Heterogeneous Photocatalysts

Findings

Conclusions and Future Outlook