Multifunctional WO₃/NiCo₂O₄ heterojunction with extensively exposed bimetallic Ni/Co redox reaction sites for efficient photoelectrochemical water splitting

Abstract

The enhanced separation and injection efficiencies of photogenerated carriers is essential to improve the photoelectrochemical (PEC) performance of WO3 photoanode. In this work, we firstly synthesized WO3/NiCo2O4 heterojunction through simple hydrothermal‐annealing method as well as investigate the effect and mechanism of NiCo2O4 on WO3 for PEC performances. The measurements demonstrate that the nano‐needle NiCo2O4 grown on the surface of WO3 induces the bimetallic Ni/Co redox reaction sites extensively exposed to the electrolyte, which is beneficial to enhance the PEC performances of WO3 photoanode, such as photocurrent density improved by four times (0.84 mA/cm2 at 1.23 V vs. RHE) as well as more negative initial potential (∼280 mV) in contrast to bare WO3. Further investigation shows the remarkable enhancement of PEC performances is attributed to improved surface reaction kinetics, the enhanced injection efficiency and separation efficiency of photogenerated carriers due to the co‐catalyst effect of NiCo2O4 and the formation of WO3/NiCo2O4 heterojunction. This work provides reference for application of heterojunction with co‐catalyst function, which is beneficial to the development and application of similar structures.

Excellent photocatalytic degradation and antibiosis of WO3/Fe2O3 heterojunction

“…The microtopographies of all as-prepared photocatalysts are investigated through the results of SEM images displayed in figure 1. As shown in figure 1(a), bare 2D WO 3 photocatalysts shows regular nanoplates array which is favourable to photocatalytic reaction of WO 3 -based photocatalysts [32]. To be more specific, all 2D WO 3 nanoplates grow almost vertically on the FTO substrate which provides direct transmission channel for photogenerated electrons, that is, photoinduced electrons are quickly transmitted to FTO and the transmission distance is shorted, thus reducing the recombination probability of photogenerated electron-hole pairs.…”

Feooh Nanolayers Decorated on Oxygen-Vacancy-Containing Bivo4 for Efficient Photoelectrochemical Degradation of Rhodamine B

“…The potential of Ag/AgCl was converted into the reversible hydrogen electrode (RHE) after the electrochemical experiment by Eq. ( 1) [32][33][34][35]:…”

Synergistic effects of nano-structured WO3-Se heterojunction decorated by organic Nafion layer on improving photoelectrochemical performance

“…Among various transition metal oxides, two dimensional (2D) tungsten trioxide (WO 3 ) is a desirable candidate possessing specific structure anisotropy, unique optical and electrical properties [8][9][10]. Mainly, monoclinic WO 3 is a superior n-type oxide with a suitable bandgap (2.5-2.8 eV), long diffusion length (∼150 nm), and high hole mobility (∼10 cm 2 V −1 S −1 ) [11][12][13]. However, the application of 2D WO 3 still need to overcome the current barriers, such as poor utilization efficiency of solar energy, fast recombination of photogenerated charge carriers, and slower oxygen evolution kinetics [14][15][16][17].…”