The water oxidation response includes a four-electron and four-proton move process, which requires a tough energy change and restricts the proficiency of the general photocatalytic water parting response.
The interfacial barrier between the semiconductor and the water oxidation cocatalyst can hinder the transfer and utilization of photogenerated charges, despite the fact that loading the right water oxidation cocatalysts can improve the performance of water oxidation reactions.
Recently, a group of researchers led by Professors A method to controllably assemble a charge-transfer mediator in photocatalysis has been developed by Li Can and Li Rengui from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS). This could improve surface charge-transfer efficiency and photocatalytic water oxidation activity. The review was distributed in Angewandte Chemie Global Version on Walk 23.
“The approach of rationally assembling charge transfer mediator provides a practical way for accelerating charge transfer and charge utilization in semiconductor photocatalysis,”Prof. Li Rengui.
The researchers used partially oxidized graphene (pGO) as a charge-transferring mediator on the hole-accumulating aspects of lead chromate (PbCrO4) photocatalyst, drawing inspiration from natural photosynthesis. Cobalt-complex Co4O4 molecules could be anchored on the pGO as a water oxidation cocatalyst using an ultrasonic deposition process on the hole-accumulating facets of PbCrO4.
They proved, using methods like surface photovoltage spectroscopy, that inserting the pGO charge transfer mediator between the hole-accumulation facets of PbCrO4 and Co4O4 molecules could effectively suppress charge recombination at the interface. This would make photogenerated charges last longer and improve the performance of photocatalytic water oxidation.
Prof. Li Rengui stated, “In semiconductor photocatalysis, the strategy of rationally assembling charge transfer mediators provides a feasible way to accelerate charge transfer and charge utilization.”
More information: Wenchao Jiang et al, Graphene Mediates Charge Transfer between Lead Chromate and a Cobalt Cubane Cocatalyst for Photocatalytic Water Oxidation, Angewandte Chemie International Edition (2023). DOI: 10.1002/anie.202302575