g-C3N4/Carbon spheres composite for efficient photoreduction and simultaneous removal of chromium

[Display omitted] •Development of a carbonaceous composite for removal of Cr (VI) from water.•Simultaneous photo-reduction and removal of Cr (VI) is achieved under visible light.•Maximum monolayer adsorption of 333.33 mg/g is obtained.•This composite can be reused at least for 5 cycles without any decrease in efficiency. A hydrothermally prepared carbonaceous composite (GCNCS) of graphitic carbon nitride (g-C3N4) and carbon spheres with band gap in visible region is reported for simultaneous photoreduction and removal of Cr(VI) from water. After 4 h of visible light irradiation, the Cr(VI) removal with GCNCS is ∼ 100% and ∼ 82% from 10 to 75 and 100 ppm Cr(VI) solutions (pH 2), respectively. The maximum adsorption capacity for GCNCS is estimated to be 333.33 mg/g and the efficiency remained constant after five continuous cycles. The efficient photo-reduction and simultaneous removal of Cr(VI) with GCNCS is thus ascribed to the g-C3N4/carbon spheres heterojunction.