Boosting Charge Separation and Transfer by Plasmon-Enhanced MoS2/BiVO4 p-n Heterojunction Composite for Efficient Photoelectrochemical Water Splitting

The poor separation and significant recombination of electron hole pairs and slow transfer mobility of charge carriers limit the performance of BiVO4 for photoelectrochemical (PEC) water splitting. To ameliorate the above problems, a novel integrated Ag-embedded MoS2/BiVO4 p-n heterojunction ternary composite electrode is fabricated and applied. Surface plasmon resonance (SPR) of Ag nanoparticles (NPs) by the near-field electromagnetic enhancement or abundant hot electrons injection and p-n heterojunction of MoS2/BiVO4 by the built-in electrical potential synergistically boost the electron hole pair separation, transfer properties and suppress the recombination of the electron hole pairs. Consequently, the BiVO4-Ag-MoS2 electrode among four of the BiVO4-based electrodes achieves the largest photocurrent density of 2.72 mA cm(-2) at 0.6 V vs RHE, which is 2.44 times higher than that of pure BiVO4 electrode (0.79 mA cm(-2)), and possesses the largest IPCE of 51% at 420 nm. This work proposes a worthy design strategy for a plasmon enhanced p-n heterojunction for efficient PEC water splitting.