Enhancing the Photoelectrochemical Water Oxidation Activity of α‐Fe2O3 Thin Film Photoanode by Employing rGO as Electron Transfer Mediator and NiFe‐LDH as Cocatalyst

다국어 초록 (Multilingual Abstract)

The shortcomings of poor charge transfer ability and slow surface water oxidation kinetics in the single component photoanode limit the performances of photocatalytic water splitting. Herein, a α‐Fe2O3/rGO/NiFe‐LDH composite photoanode was designed for enhancing photoelectrochemical (PEC) water oxidation activity. The rGO nanosheets serve as an efficient electron transfer mediator for promoting charge transport and separation. The NiFe‐LDH is well anchored on rGO nanosheets and provides additional active sites for accelerating water oxidation reaction kinetics. By the virtue of synergistic effect between rGO and NiFe‐LDH, the composite photoanode achieves a pronounced photocurrent density of 1.46 mA/cm2 at 1.23 VRHE (V vs. reversible hydrogen electrode), which is 2.86 times of α‐Fe2O3. Moreover, the onset potential exhibits a significant cathodic shift of 230 mV. This work provides a valuable strategy for the design of photoanode with light absorber, rGO electron transfer mediator and other cocatalysts to achieve efficient and stable PEC water splitting.
A α‐Fe2O3 composite photoanode with rGO as charge transfer mediator and NiFe‐LDH as cocatalyst was successfully fabricated via spin‐coating method followed by photo‐assisted electrodeposition technology for water photo‐oxidation. Attributed to the synergistic effect between rGO and NiFe‐LDH, simultaneous enhancement in charge transfer and water oxidation kinetics of α‐Fe2O3 photoanode was demonstrated. As a result, the α‐Fe2O3/rGO/NiFe‐LDH composite photoanode displays the excellent photoelectrochemical (PEC) performance.