In-depth　understanding　the　dye　sensitization　process　over　the　semiconductor　is　the　key　issue　for　the　applications　of　dye-sensitized　solar　cells,　hydrogen　production,　and　environmental　remediation.　This　work　addresses　the　role　of　high-quality　BiOCl　nanoplates　in　the　photosensitization　process.　It　is　found　that　there　exists　a　strong　interaction　between　Rhodamine　B　and　BiOCl　nanoplates,　which　greatly　improves　the　electronic　conductivity　for　interfacial　electron　injection.　The　fluorescence　emission　of　Rhodamine　B　is　thus　markedly　suppressed　by　the　addition　of　BiOCl　suspension,　resulting　from　the　electron　injection　from　excited　Rhodamine　B　into　the　conduction　band　of　BiOCl　nanoplates.　Moreover,　benefitting　from　the　proper　conduction　band　edge　potential　of　BiOCl　nanoplates,　the　injected　electrons　can　be　trapped　by　the　surface　absorbed　O2　to　generate　reactive　oxygen　species,　resulting　in　the　high　photosensitization　activity　for　the　Rhodamine　B　degradation　under　visible　light　irradiation.　©　2014　Elsevier　B.V.