Design and construction of a novel hierarchical Ag/{111}Ag3PO4/PANI/Pt photoanode with boosted interfacial charge transfer rate and high photocurrent density > 16 mA/cm2 for sunlight-driven water splitting

• Published in: Energy conversion and management Vol. 271; p. 116298
• Main Authors: Ng, Wen Cai, Saha, Tridib, Ilankoon, IMSK, Chong, Meng Nan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-11-2022
• Subjects: Conductive polymer; Hole-transfer layer; Photoelectrocatalytic; Platinum co-catalysts; Silver orthophosphate; Silver orthophosphate; Conductive polymer; Platinum co-catalysts; Hole-transfer layer; Photoelectrocatalytic
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2022.116298

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•A record photocurrent density of 16.34 mA/cm2 was achieved under AM 1.5 G.•PANI-{111}Ag3PO4 forms a p-n junction with excellent hole-transporting property.•The Pt NPs show synergistic effects on electron-trapping and light harvesting.•EIS and TRPL results validated the superior charge transfer rate of the photoanode.
In this work, a novel hierarchical photoanode structure of Ag/{111}Ag3PO4/PANI/Pt was synthesized, demonstrating a novel and facile approach to design a high-performing Ag3PO4-based photoanode for visible-light-driven solar green hydrogen (H2) generation. The Ag3PO4 photoanode with carefully curated active facets, Ag/{111}Ag3PO4, was interfaced with a conductive polyaniline (PANI) thin film and surface decorated with platinum nanoparticles (Pt NPs) to realise the combined advantages of integrating both PANI and Pt NPs as a hole-transporting layer and co-catalysts, respectively. This novel photoanode achieved a record photocurrent density of 16.34 mA/cm2 at 1.4 V vs Ag/AgCl under AM 1.5 G solar irradiation (100 mW/cm2), which outperformed that of the bare Ag/{111}Ag3PO4 photoanode and is also the highest photocurrent density reported to date for Ag3PO4-based photoanodes. The PEC enhancement is attributed to the new exploitation of the PANI-{111}Ag3PO4p-n heterojunction, the hole-transporting property of PANI and the electron-capturing capability of Pt NPs, in which their synergetic interactions effectively led to improved light absorption, enhanced charge separation and reduced charge recombination. It is foreseen that this current work can provide a base for further nanoarchitectural design strategies to construct efficient photoanodes used in PEC water splitting application.