A Semiconductor‐Mediator‐Catalyst Artificial Photosynthetic System for Photoelectrochemical Water Oxidation

Abstract

In fabricating an artificial photosynthesis (AP) electrode for water oxidation, we have devised a semiconductor‐mediator‐catalyst structure that mimics photosystem II (PSII). It is based on a surface layer of vertically grown nanorods of Fe2O3 on fluorine doped tin oxide (FTO) electrodes with a carbazole mediator base and a Ru(II) carbene complex on a nanolayer of TiO2 as a water oxidation co‐catalyst. The resulting hybrid assembly, FTO|Fe2O3|−carbazole|TiO2|−Ru(carbene), demonstrates an enhanced photoelectrochemical (PEC) water oxidation performance compared to an electrode without the added carbaozle base with an increase in photocurrent density of 2.2‐fold at 0.95 V vs. NHE and a negatively shifted onset potential of 500 mV. The enhanced PEC performance is attributable to carbazole mediator accelerated interfacial hole transfer from Fe2O3 to the Ru(II) carbene co‐catalyst, with an improved effective surface area for the water oxidation reaction and reduced charge transfer resistance.

Organic Upgrading through Photoelectrochemical Reactions: Toward Higher Profits

“…[12][13][14][15] Even though hydrogen production by PEC water splitting has been known as the ultimate clean energy production system that converts light energy into hydrogen molecules, the development of water splitting encounters many difficulties in increasing its efficiency, especially due to the poor kinetics of the OER. [16][17][18][19][20] The OER utilizes a four-electron transfer mechanism that requires a high overpotential and exhibits poor kinetics. [21][22][23][24][25] Moreover, photoelectrodes are often degraded during the OER due to the self-oxidation of the electrode by the exciton.…”

The Influence of Lyophobicity and Lyophilicity of Film-Forming Systems on the Properties of Tin Oxide Films

“…The bandgap is reduced and the oxidation potential of holes is improved by doping the material with fluorine atoms [24,25]. Tin oxide films doped with fluorine and indium [26] are used in photocatalysis [27][28][29], perovskite solar cells [30][31][32], electrochemistry [33][34][35], and biosensors [36][37][38]. Great success in obtaining films of tin oxide doped with fluorine has been achieved using the sol-gel method.…”