One-dimensional WO3/BiVO4 heterojunction photoanodes for efficient photoelectrochemical water splitting

In the present work, we reported the exploration of WO 3 /BiVO 4 heterojunction photoanodes, which were consisted of one-dimensional WO 3 nanofiber (1D-WO 3 ) cores and BiVO 4 film shells. The 1D-WO 3 nanofibers were prepared by electrospinning, and the BiVO 4 outlayers were subsequently deposited around the surface of 1D-WO 3 fibers via a solution immersion process, leading to the construction of 1D-WO 3 /BiVO 4 heterojunctions. They had a maximum photocurrent density of 2.8 mA cm −2 at 1.23 V vs. RHE under AM 1.5 simulated solar light illumination, which was ∼20 times to that of pure 1D-WO 3 counterparts ( i.e. , 0.15 mA cm −2 ), and comparable to the best one of photoanodes based on WO 3 /BiVO 4 hybrids ever reported. Furthermore, the onset potential of FTO/1D-WO 3 /BiVO 4 photoanode was subsequently reduced, and the maximum incident photon-to-current efficiency ( IPCE ) was enhanced for ∼4 times in comparison to that of 1D-WO 3 counterparts. The mechanism for the enhanced PEC behaviors of WO 3 /BiVO 4 heterojunction photoanodes was proposed.