High Performance Ferroelectric‐modulated Photoelectrodes by Using Grid Charge Collector

Metal oxide‐based photoelectrochemicals (PEC) are promising for solar‐fuel conversion if the issues of excessive charge carrier recombination in bulk can be resolved. Ferroelectric modulation of photoelectrodes is a remedial strategy but is less available due to the contradiction between the screening effect and free carrier collection. This work designed and fabricated a novel ferroelectric‐modulated photocathode (p‐type CuBi2O4/PbZrTiO, CBO/PZT) with gird‐like gold (G‐Au) charge collector under theoretical guidance. Several characterizations, including Multiphysics simulations and optoelectronic and interfacial electronic energy levels calculations, proved the critical role of the G‐Au charge collector in decoupling charge collecting and screening. As a result, the positively polarized photocathode exhibited the best performance with an average H2O2 concentration around 1.5 mol (L h m2)−1. Thus, this work demonstrated the successful integration of ferroelectric in PEC photoelectrodes with improved photocarrier collection using a grid metal collector, which can be broadly applied to other optoelectronic systems. A grid‐Au layer is used as the charge collector inserted between the photocathode (CuBi2O4) and the ferroelectric ceramics PbZrTiO plate, with the ability to balance the contradiction between charge collecting and screening effect, and thus break the bottleneck of small polaron limited charge collection efficiency.