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

In the present work, we reported the exploration of WO3/BiVO4 heterojunction photoanodes, which were consisted of one-dimensional WO3 nanofiber (1D-WO3) cores and BiVO4 film shells. The 1D-WO3 nanofibers were prepared by electrospinning, and the BiVO4 outlayers were subsequently deposited around the surface of 1D-WO3 fibers via a solution immersion process, leading to the construction of 1D-WO3/BiVO4 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-WO3 counterparts (i.e., 0.15 mA cm−2), and comparable to the best one of photoanodes based on WO3/BiVO4 hybrids ever reported. Furthermore, the onset potential of FTO/1D-WO3/BiVO4 photoanode was subsequently reduced, and the maximum incident photon-to-current efficiency (IPCE) was enhanced for ∼4 times in comparison to that of 1D-WO3 counterparts. The mechanism for the enhanced PEC behaviors of WO3/BiVO4 heterojunction photoanodes was proposed.