Indoor light boosted formaldehyde abatement over electrostatic self-assembled graphitic carbon nitride/ceric oxide at ambient temperature

The pursuit of efficient noble metal-free catalysts is highly desirable for possible practical application of ambient-temperature removal of indoor formaldehyde (HCHO). In this work, graphitic carbon nitride/ceric oxide (g-C3N4/CeO2) heterojunctions were prepared via a simple electrostatic self-assembly method, which possessed moderate catalytic performances for HCHO elimination in the dark at ambient temperature. Indoor fluorescent-light irradiation obviously sped up the conversion of HCHO into CO2 and H2O over g-C3N4/CeO2 heterojunctions. Particularly, C3N4/CeO2 with theoretical 20 wt% of g-C3N4 (20%g-C3N4/CeO2) exhibited a HCHO removal efficiency of ca. 73% and HCHO conversion ratio of ca. 70% under fluorescent-lamp illumination, higher than the corresponding ones of 47% and 26% in the dark, respectively. The fluorescent-lamp irradiation promoting HCHO degradation over C3N4/CeO2 was proposed on the basis of the visible-light response of individual g-C3N4 and CeO2, and the distinct heterostructure conducive to the separation of photo-generated carriers as well as intrinsic capability of CeO2 favoring the formation of extra active oxygen species. This work might provide a vane of energy saving and emission reduction by taking full advantage of indoor lights for environmental remediation.