Facile and Large-Area Preparation of Porous Ag₃PO₄ Photoanodes for Enhanced Photoelectrochemical Water Oxidation

Abstract

Photoelectrochemical (PEC) water splitting is a promising approach for renewable energy, where the development of efficient photoelectrodes, especially photoanodes for water oxidation is still challenging. In this paper, we report the novel solution-processed microcrystalline AgPO photoanodes with tunable porosity depending on the reaction time. These porous AgPO films were grown on large-area (4.5 × 4.5 cm) silver substrates via an air-exposed and room-temperature immersion reaction. Enhanced light absorption abilities were exhibited by the synthesized AgPO films with optimized porosity resulted from prolonged reaction times (≥20 h), due to which appreciable water splitting performance was demonstrated when they were utilized as photoanodes. Particularly, the highly porous 20 h AgPO photoanode presented a photocurrent density of around 4.32 mA/cm, which is nearly three times higher than that of the nonporous 1 h AgPO photoanode (1.48 mA/cm) at 1 V vs Ag/AgCl. Moreover, superior stability of the 20 h AgPO photoanode has also been confirmed by the 5 h successive PEC water splitting experiment. Therefore, both the scalable and facile fabrication method, and considerable photoactivity and stability of these AgPO photoanodes together suggest their great potential for efficient solar-to-fuel energy conversion and other PEC applications.

Recent progress in iron oxide based photoanodes for solar water splitting

“…Grätzel et al demonstrated a large area device (10 cm × 10 cm) with an illumination area of 80 cm [2] which yielded a total photocurrent of 35 mA which translates to a current density of 0.43 mA cm −2 [69]. Cao et al reported large area preparation of porous Ag 3 PO 4 photoanodes with a photocurrent density of around 4.32 mA cm −2 at 1 V versus Ag/AgCl (equivalent to 1.86 V versus RHE for pH 11.3 Na 3 PO 4 electrolyte) with a 5 h successive PEC water splitting experiment [200]. We have been developing large area hematite photoanodes on FTO substrate consisting an illumination area of up to 7 cm [2].…”

Facile controlled synthesis of Ag3PO4 with various morphologies for enhanced photocatalytic oxygen evolution from water splitting

“…25,26 They have also been synthesized by using different organic additives, with these syntheses apparently proceeding according to the oriented aggregation mechanism: organic compounds containing Ag and a ligand complex were formed, followed by their having reacted with other compounds, then crystal nuclei having formed gradually and growing further, and nally with selfassembly and oriented aggregation having been realized. Different sizes and morphologies were produced using different templates such as polycarbonate membranes, 27 vinyl pyrrolidone (PVP), 28,29 and polyhedral Ag 3 PO 4 microcrystals. 30 The prepared parameters including reaction components, 25,26 temperature, and time, 31 usually play a vital role in tailoring the morphologies and structures of Ag 3 PO 4 crystals.…”

Metal–Organic-Framework-Derived Ball-Flower-like Porous Co3O4/Fe2O3 Heterostructure with Enhanced Visible-Light-Driven Photocatalytic Activity

“…In photocatalysis systems, CF demonstrated a superior performance than Co-TDC and Fe 2 O 3 , indicating that CF possesses the highest photocatalytic activity. This could be explained by the following aspects: (i) The highly porous structure of CF provided abundant active sites, as revealed in Figure 2b,c [24][25][26];…”