Enhanced Charge Transfer by Passivation Layer in 3DOM Ferroelectric Heterojunction for Water Oxidation in HCO₃⁻/CO₂ System

Abstract

Photoelectrochemical carbon dioxide conversion to fuels such as carbon monoxide, methanol, and ethylene exhibits great potential to solve energy issues. Unfortunately, CO2 conversion efficiency is still low due to violent charge recombination at the photoanode. Herein, a novel 3D macroporous ferroelectric heterojunction composed of BiFeO3 and LiNbO3 is developed by a template‐assisted sol–gel method, aiming at facilitating charge transfer kinetics. As expected, a tremendous enhancement of photocurrent density (300 times vs bare planar BiFeO3 film) and charge transfer efficiency (up to 76%) is obtained in the HCO3−/CO2 system without any cocatalyst. The photoelectrochemical performance is switchable by poling to form a depolarization electric field. Photoelectrochemical impedance spectroscopy reveals that the charge transfer resistance decreases due to the synergistic effect of BiFeO3 3D macroporous skeleton and LiNbO3 passivation layer by tuning surface states. These results suggest a novel strategy for enhancing photoelectrochemical water oxidation as the anodic reaction of CO2 reduction.

Engineering Nanostructure–Interface of Photoanode Materials Toward Photoelectrochemical Water Oxidation

“…[33][34][35] As intrinsic semiconductor materials, both wide and narrow bandgap semiconductor photoanode materials are suffering from the poor bulk-phase carrier separation, intense surficial e − /h + trapping recombination, and sluggish electrode/electrolyte carrier injection kinetics. [36][37][38][39] Fortunately, with the continuous investment of researchers, a series of modification methods have been established and the PEC water oxidation performance of semiconductor photoanode materials has been significantly improved. [32,[40][41][42][43][44] Among various strategies, nanostructure-interface engineering is widely regarded as an effective method to improve the PEC water oxidation performance: [40,41] the light-harvesting performance can be enhanced by the widened optical Photoelectrochemical (PEC) water oxidation based on semiconductor materials plays an important role in the production of clean fuel and value-added chemicals.…”

Narrow Bandgap Inorganic Ferroelectric Thin Film Materials

“…The composition reaction changes of the preparation in thin film materials can be sorted into physical and chemical methods. These include physical methods such as RF magnetron sputtering, [90][91] pulsed laser deposition (PLD), [92][93] RF magnetron sputtering, [90][91] molecular beam deposition (MBD), [94][95][96] and thermal evaporation, [97][98][99] and chemical methods such as sol-gel method, [100][101][102][103][104][105][106] metal-organic chemical vapor deposition (MOCVD), [107][108][109][110] and metal-organic decomposition (MOD) methods. [111] The later discussion will focus on the different preparation methods of PLD and the sol-gel method.…”

Progress and perspectives on 1D nanostructured catalysts applied in photo(electro)catalytic reduction of CO2

“…To further improve the performance of photo(electro)catalytic CO 2 RR, researchers have made great efforts in recent years. In the development of advanced catalysts, the materials are mainly modified around a supporting non-precious metal, 33–35 combined with molecular catalysts, 36–38 a heterojunction is constructed, 39–41 localized surface plasmon resonance (LSPR) is introduced, 42–45 or element doping is done. 46–51 At the same time, several excellent review articles have analyzed in detail around the above aspects.…”