Graphene modified “black {0 0 1}TiO2” nanosheets for photocatalytic oxidation of ethylene: The implications of chemical surface characteristics in the reaction mechanism

•Fluorine free TiO2 NSTs with {001} facets were synthesized via a solvothermal route.•rGO-B-TiO2 NSTs with a 94% exposed {001} facets and oxygen vacancies were obtained.•Ethylene chemisorption over rGO-B-TiO2 NSTs was identified by operando DRIFTS.•Humidity favours ethylene oxidation at active surface sites of rGO-B-TiO2 NSTs.•rGO increases excitons’ mobility, enhancing photocatatytic yield of rGO-B-TiO2 NSTs.