Low　light-absorption　capacity　and　separation　efficiency　of　photo-generated　charges　are　two　major　limit　factors　to　achieve　high　performance　of　photocatalysts.　Herein,　porous　core-shell　TixSn1-xO2　solid　solutions　with　effective　light-absorption　capacity　and　charge　separation　are　fabricated　through　one-pot　mild　solvothermal　method　without　any　surfactant　and　template.　The　self-development　mechanism　of　the　porous　core-shell　microspheres　includes　prior　Ti-alkoxide　hydrolysis　and　the　spontaneous　nucleation　of　TixSn1-xO2　combined　with　Ostwald　ripening.　Interestingly,　although　both　TiO2　and　SnO2　are　wide　band　gap　semiconductors,　the　prepared　yellow　TixSn1-xO2　solid　solutions　are　of　controllable　band　structure　and　broad-light　response　capacity.　When　Ti:Sn　molar　ratio　is　7:3,　the　Ti0.7Sn0.3O2　sample　shows　the　highest　MO-photodegradation　rate　constant　of　0.62　min−1　under　UV　irradiation,　exceeding　that　of　commercial　TiO2　(0.04　min−1)　by　more　than　15　times.　Particularly,　the　sample　also　exhibits　ultrahigh　photocatalytic　activity　in　MO-photodegradation　(0.038　min−1)　and　As(III)　removal　(up　to　100%)　under　visible-light　(≥420　nm)　irradiation.　The　mechanism　study　reveals　that　due　to　the　proper　redox　potential　of　SnIV/SnII　and　the　structural　defects　(e.g.,　oxygen　vacancies)　caused　by　lattice　distortion,　the　photogenerated　electrons　would　be　trapped　and　the　holes　act　as　the　main　active　species　for　the　photooxidation　reaction　of　MO　and　As(III)　over　TixSn1-xO2　photocatalysts.　©　2018　Elsevier　B.V.