Abstract
A facile fabrication of MoOxSy-CoPI photocatalyst revealed a conformal growth of nanoflowers. The photoelectrochemical studies exhibited significantly enhanced photocurrents with a stable and repeatable photocurrent response under visible light (1SUN) simulated solar irradiation.
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•Facile synthesis of Molybdenum oxysulphide-cobalt phosphate (MoOxSy-CoPi) novel material for solar water splitting.•The MoOxSy-CoPI photocatalyst corresponded to the most stable oxidation states of Mo, Co, S, P, and O in the composite.•Nanoflowers of MoOxSy-CoPI showed controlled thickness up to ∼10 nm, and variable interspaces of 200-400 nm were produced.•Band-gap energy of 2.44 eV and significantly higher (7-8 folds) photocurrent density of MoOxSy-CoPI is recorded compared to MoOxSy and CoPI.
Hydrogen is considered as a clean alternative green energy future fuel. Since the Honda-Fujishima effect for photoelectrochemical water splitting is known, there has been a substantial boost in this field. Numerous photocatalysts based on metals, semiconductors, and organic-inorganic hybrid-systems have been proposed. Several factors limit their efficiency, e.g., a stable PEC-WS setup, absorbing visible light, well-aligned band energy for charge transfer, electrons and holes, and their separation to avoid recombination and limited water redox reactions. Metallic doping and impregnation of stable and efficient co-catalysts such as Pt, Ag, and Au showed enhanced PEC-WS. We used Cobalt-based co-catalyst with molybdenum oxysulfide photocatalyst for effectual solar-driven water splitting.
To develop photocatalysts for efficient PEC processes capable of absorbing sufficient visible light, good band energy for effective charge transfer, inexpensive, significant solar-to-chemical energy conversion efficiencies. Above all, it is developing such PEC-WS systems that will be commercially viable for renewable energy resources.
We prepared Molybdenum oxysulphide-cobalt phosphate photocatalyst for PEC-WS through a facile hydrothermal route using ammonium heptamolybdate, thiourea, and metallic Cobalt precursors.
An effectual photocatalyst is produced for solar-driven water splitting. The conformal morphology of MoOxSy-CoPi nanoflowers is a significant feature, as observed under FE-SEM and HR-TEM. XRD confirmed the degree of purity and orthorhombic crystal structure of MoOxSy-CoPi. EDX and XPS identify the elemental compositions and corresponding oxidation states of each atom. A 2.44 eV band-gap energy is calculated for MoOxSy-CoPi from the diffused reflectance spectrum. Photo- Electrochemical Studies (PEC) under 1-SUN solar irradiation revealed 7-8 folds enhanced photocurrent (∼ 3.5 mA/cm2) generated from MoOxSy-CoPi/FTO in comparison to Co-PI/FTO (∼ 0.5 mA/cm2) and MoOxSy-/FTO respectively, within 0.5 M Na2SO4 electrolyte (@pH=7) and standard three electrodes electrochemical cell.
Our results showed MoOxSy-CoPi as promising photocatalyst material for improved solar-driven photoelectrochemical water splitting system.