Photo-responsive　adsorption-photocatalysis　nanocomposites　are　generally　used　in　water　and　wastewater　decontamination;　however,　the　prolonged　adsorption　capacity　of　composites　and　the　role　of　adsorption　in　concomitant　photocatalysis　are　typically　neglected.　These　composites　can　be　regenerated　under　light　irradiation　as　their　adsorption　capacity　decreases.　Herein,　a　novel　adsorption-photocatalysis　bifunctional　nanocomposite,　Bi-doped　TiO2　supported　on　powdered　activated　carbon　(Bi2O3/TiO2/PAC),　was　prepared　using　the　sol-impregnation-hydrothermal　procedure.　Bi2O3/TiO2/PAC　with　a　secondary　calcination　temperature　of　700　degrees　C　under　a　nitrogen　atmosphere　was　selected　for　maximum　adsorption　capacity　on　Methyl　Orange　(MO).　The　composite　displayed　an　excellent　adsorption　capacity　and　was　easily　separated　and　recycled.　The　results　demonstrate　that　71.2%　photocatalytic　regeneration　efficiency　could　be　attained　under　visible　light　irradiation　for　1　hr　at　an　intensity　of　750　W/m(2)　and　pH　7.　Characterization　of　the　as-prepared　Bi2O3/TiO2/PAC　nanocomposite　(700　degrees　C)　indicates　that　it　possesses　a　highly　specific　surface　area　and　great　optical　properties,　showing　bifunctional　adsorption-photocatalysis　characteristics.　The　p-n　heterojunction　of　the　composite　played　a　dominant　role　in　the　photocatalytic　regeneration　process,　and　effective　degradation　of　MO　could　be　achieved　along　with　composite　regeneration.　(C)　2020　Published　by　Elsevier　B.V.　on　behalf　of　The　Research　Centre　for　Eco-Environmental　Sciences,　Chinese　Academy　of　Sciences.