Bismuth vanadate (BiVO₄) is one of the n-type semiconductors which has attracted attention as one of the promising photoanodes semiconductor for photoelectrochemical water splitting due to its small optical band gap, low cost, negative conduction band edge and good stability. In this work, BiVO₄ thin films is fabricated by using electrodeposition method and the XRD spectra reveal that the sample crystallizes in monoclinic scheelite type. The optical bands show the bandgap energy of BiVO₄ thin films is 2.40 eV as determined by Tauc plot and exhibits an anodic photocurrent. Further study is focusing on determination of the conduction band (CB) and valence band (VB) of BiVO₄ thin films which is derived experimentally by using XPS analysis, Mott–Schottky plot and Cyclic Voltammetry (CV) technique. Based on the results, it is found that different analysis techniques exhibit almost similar values of CB and VB of BiVO₄ thin films. All techniques give VB maximum in the range of 2.02 eV–2.05 eV and CB minimum in the range of −0.35 eV to −0.39 eV. However, the flat-band potential determined from Mott–Schottky plot is nearly 0.1 eV from CB potential caused by the presence of Fermi level and the effect of Helmholtz capacitance for dielectric semiconductors. These findings clearly show that the experimental values of different analysis techniques give comprehensive approach to understanding the energy band structure of the BiVO₄ thin films.

钒酸铋（BiVO ₄）是一种n型半导体，由于其光学带隙小，成本低，导带负边缘和稳定性好等优点而成为一种有前景的光电化学水分解用光阳极半导体之一。本文采用电沉积法制备BiVO ₄薄膜，XRD谱图表明样品以单斜白钨矿型结晶。光学带显示，根据Tauc图，BiVO ₄薄膜的带隙能量为2.40 eV，并显示出阳极光电流。进一步的研究集中在确定BiVO ₄的导带（CB）和价带（VB）薄膜是通过XPS分析，Mott-Schottky图和循环伏安法（CV）技术实验得出的。根据结果​​，发现不同的分析技术表现出BiVO ₄薄膜的CB和VB几乎相似的值。所有技术均使VB最大值在2.02 eV–2.05 eV范围内，而CB最小值在-0.35 eV至-0.39 eV范围内。然而，由莫特-肖特基图确定的平带电势，由于费米能级的存在和亥姆霍兹电容对介电半导体的影响而导致的CB电势接近0.1 eV。这些发现清楚地表明，不同分析技术的实验值为理解BiVO ₄薄膜的能带结构提供了全面的方法。