Bismuth oxychloride has emerged as an important material for photoelectrochemical, photocatalysis and photovoltaic application. Its unique crystal structure of alternating sheets of [BiO₂]²⁺ and two Cl^-1 along the c-axis, leads to the formation of an internal electrical dipole, facilitating faster electron-hole separation. It has a p-type conductivity with a bandgap of ~3.4 eV and its band edge position is suitable for photelectrochemical water reduction.

In this study, BiOCl films with 3 different morphologies are synthesized by the chemical vapor deposition process and the effect of sample morphology on the photoelectrochemical behavior is studied. BiOCl is deposited on transparent electrodes by thermal vapor transport of BiCl₃ precursors. Figure 1(a-c) shows the as deposited microwall, micropore and microflower morphologies of BiOCl, obtained by finely controlling the deposition conditions

The photoelectrochemical cells fabricated using the as grown micropore morphology showed the highest photocurrent. The micropore structure allows solution penetration into the pores thus providing faster charge transport pathways. Structural investigation will be presented using SEM, XRD and Raman spectroscopy. This work demonstrates that tailoring the BiOCl surface morphology can lead to efficient photoelectrochemical water reduction.