Carbon　wrapped　and　doped　mesoporous　anatase　TiO2　nanocrystals　were　prepared　by　a　hydrothermal　approach　in　acetic　acid　aqueous　containing　chitosan.　A　designed　post-thermal　treatment　was　employed　to　enhance　the　incorporation　between　carbon　and　TiO2.　After　hydrothermal　process,　mesoporous　anatase　TiO2　formed　with　wrapped　by　a　few　layers　of　carbon　shell.　Here　chitosan　was　used　as　not　only　the　template　for　the　formation　of　mesopores,　but　also　the　carbon　source　toward　the　carbon　layers　coating.　Furthermore,　chitosan　provided　doping　element　into　TiO2　lattice　and　induced　to　form　Ti-C　bond　which　caused　Ti(III)　with　oxygen　vacancies.　The　Ti(III)-oxygen　vacancy　are　partly　responsible　for　visible-light　response　and　high　photocatalytic　activity,　which　can　accelerate　electron　transfer　thus　inhibit　photogenerated　charge　recombination.　The　photocatalytic　activity　was　evaluated　using　photo-oxidation　of　gaseous　NO　under　visible　light　irradiation　as　the　probe　reaction.　In　the　optimum　result,　71%　of　NO　with　starting　concentration　at　ppb　level　was　photo-degraded.　Our　results　also　showed　that　the　photogenerated　electrons　played　a　key　role　in　photodegradation　of　NO,　as　a　result,　the　environmental　humidity　level　had　a　negligible　effect　on　the　photocatalysis.　(C)　2016　Elsevier　B.V.　All　rights　reserved.