Photoreactivity　for　photodegradation　of　2-NAP　on　BiOCl　nanosheets　with　dominant　exposed　(010)　and　(001)　facets　is　studied　under　visible　light　via　an　exciton-free　and　nonsensitized　mechanism.　This　phenomenon　cannot　be　explained　by　semiconductor　theory　or　self-sensitized　(as　those　involve　dyes)　mechanisms.　The　photocatalytic　activities　are　mainly　owing　to　the　formation　of　the　surface　state,　which　is　confirmed　to　be　the　surface　complex　Bi-O-C10H7.　This　surface　complex　is　characterized　with　ultraviolet　visible　diffuse　reflectance　spectra,　Fourier　transformed　infrared　spectroscopy,　Raman　scattering,　X-ray　photoelectron　spectroscopy,　and　photoelectrochemical　measurement.　The　optical　absorptivity　of　BiOCl　is　shifted　from　the　ultraviolet　light　toward　the　visible　light　via　a　charge-transfer-complex　pathway.　Charge　transfer　after　the　excitation　of　visible　light　induces　efficient　visible　photocatalytic　activities.　The　results　show　that　single-crystalline　BiOCl　nanosheets　exposing　(010)　facets　exhibit　higher　photoactivity　due　to　more　surface　complex　and　more　terminal　bismuth　atoms　on　the　surface　of　BiOCl　(010).　Our　current　work　is　expected　to　offer　new　insight　into　photocatalytic　theory　for　better　understandings　to　photocatalytic　reactions　and　for　rational　design　and　synthesis　of　photocatalyst　with　high　activity.