Significantly Promoting the Photogenerated Charge Separation by Introducing an Oxygen Vacancy Regulation Strategy on the FeNiOOH Co‐Catalyst

Abstract

Semiconductor/co‐catalyst coupling is considered as a promising strategy to enhance the photoelectrochemical (PEC) conversion efficiency. Unfortunately, this model system is faced with a serious interface recombination problem, which limits the further improvement of PEC performances. Here, a FeNiOOH co‐catalyst with abundant oxygen vacancies on BiVO4 is fabricated through simple and economical NaBH4 reduction to accelerate hole transfer and achieve efficient electron–hole pair separation. The photocurrent of the BV (BiVO4)/Vo‐FeNiOOH system is more than four times that of pure BV. Importantly, the charge transfer kinetics and charge carrier recombination process are studied by scanning photoelectrochemical microscopy and intensity modulated photocurrent spectroscopy in detail. In addition, the oxygen vacancy regulation proposed is also applied successfully to other semiconductors (Fe2O3), demonstrating the applicability of this strategy.

Metal‐Organic Framework Glass Catalysts from Melting Glass‐Forming Cobalt‐Based Zeolitic Imidazolate Framework for Boosting Photoelectrochemical Water Oxidation

“…Co‐a g ZIF‐62/NiO/BiVO 4 has the highest K trans and the lowest K rec among these samples, indicating that NiO HTL greatly accelerates the charge transfer rate from BiVO 4 to Co‐a g ZIF‐62 and Co‐a g ZIF‐62 catalyst can effectively facilitate the charge transfer to the surface, thus reducing surface recombination. Noteworthily, Co‐a g ZIF‐62/NiO/BiVO 4 shows the highest charge transfer efficiency (Figure 5f), which means higher PEC water oxidation performance [64–66] …”

“…Noteworthily, Co-a g ZIF-62/ NiO/BiVO 4 shows the highest charge transfer efficiency (Figure 5f), which means higher PEC water oxidation performance. [64][65][66] The continuous stability of photoanodes is the noteworthy factor to evaluate the practical PEC application. Current-time curves were performed to test the photocurrent stability of the photoanodes.…”

Elemental doping inhibits surface-state-mediated charge carrier trapping for promoting photocatalytic selective oxidation

“…These results clearly prove the suppressed consumption of photoinduced charge carriers in V-Bi 2 O 2 CO 3 . [21][22][23][24] Besides, the potential impacts of electrical conductivity on the photocurrent spike were excluded by electrochemical impedance spectroscopy (EIS) measurements (Fig. S8 †).…”

Unveiling the Synergy of Interfacial Contact and Defects in α‐Fe2O3 for Enhanced Photo‐Electrochemical Water Splitting

“…[16,24,25] Engineering intrinsic defects with oxygen vacancies at the interfacial surface is an important method in speeding up hole transfer and strengthening the adsorption of oxidative intermediates to improve the OER catalytic activity. [26][27][28][29] Thus, for a much-increased OER activity, both optimizing the interfacial charge-transfer kinetics and strengthening the adsorption of oxidative intermediates for effectively driving water oxidation are indispensable. [24,30,31] Although many experiments have been conducted, a more precise understanding of the synergy between interfacial contact and defects is still lacking.…”