Herein,　Bi1-xFexVO4(x=0,　0.05,　0.10,　0.25,　0.40)　thin　films　were　prepared　on　fluorine-doped　tin　dioxide(FTO)　conductive　glasses　by　one-step　drop-coating　approach,　and　their　structural,　morphological,　optical　and　photoelectrochemical(PEC)　properties　were　characterized.　It　is　found　that　Bi1-xFexVO4　thin　films　with　Fe　addition　show　the　better　PEC　performance　compared　with　BiVO4　thin　film.　At　the　potential　of　1.23　V(vs.　RHE),　a　highest　photocurrent　density　of　0.50　mA/cm2　for　water　oxidation　is　obtained　for　25%　Fe-BiVO4(the　actual　Fe　content　is　22.5%)　thin　film　in　0.1　mol/L　potassium　phosphate　buffer　solution(pH=7.0),　which　is　three　times　higher　than　that　of　BiVO4　thin　film.　Combined　with　X-ray　diffraction(XRD),　Raman　spectroscopy　and　X-ray　photoelectron　spectroscopy(XPS)　analyses,　it　is　confirmed　that　Fe3+　presents　in　form　of　FeVO4　in　the　Bi1-xFexVO4　thin　films,　thus　actually　a　BiVO4/FeVO4　composite　film　is　prepared.　The　UV-Vis　measurements　reveal　that　all　the　Bi1-xFexVO4　thin　films　exhibit　an　optical　band　gap　of　2.4-2.5　eV.　After　eliminating　the　effort　of　iron-based　OER　catalysts,　the　improved　PEC　activity　of　25%　Fe-BiVO4　thin　film　could　be　attributed　to　the　increment　of　charge　transfer　efficiency(ηtrans)　and　separation　efficiency(ηsep),　which　is　also　verified　by　electrochemical　impedance　spectroscopy(EIS)　tests.　The　flat　band　potentials　of　BiVO4　and　FeVO4　thin　films　are　determined　to　be　0.10　V　and　0.42　V(vs.　RHE)　from　Mott-Schottky　measurements.　Based　on　the　measured　optical　band　gap　and　flat　band　potential,　a　schematic　diagram　of　band　structure　is　plotted,　and　the　result　displays　that　a　type　band　alignment　is　formed　between　BiVO4　and　FeVO4,　which　could　promote　the　separation　and　transfer　of　photogenerated　electron-hole　pairs.　Therefore,　the　mechanism　for　the　improved　PEC　performance　of　25%　Fe-BiVO4　thin　film　could　be　explained　by　favorable　separation　and　transfer　of　carriers　resulted　from　the　type　band　alignment.　©　2021,　Editorial　Department　of　Chem.　J.　Chinese　Universities.　All　right　reserved.