As for photocatalytic oxidation of nitric oxide (NO), the low NO oxidation activity and generation of by-products (cf. NO2) are the urgent challenge. To tackle these issues, a simple in-situ growing stragegy was employed to constructe Ti3C2/g-C3N4 system. The fabricated Ti3C2/g-C3N4 composite (TC-CN) presented enhanced photocatalytic NO removal efficiency and inhibited toxic NO2 generation. Density functional theory (DFT) calculations and experimental characterizations were combined to demonstrate the presence of strong interface effect between Ti3C2 and g-C3N4, which could greatly improve photo-generated charge carrier separation via the construction of electron transfer channels, and further activate oxygen molecules adsorbed on the side of Ti3C2 layer. As a result, nitrite and nitrate instead of NO2 were the final products during the photocatalytic reaction process through the monitoring by in situ diffuse reflectance infrared spectroscopy (DRIFTS). (C) 2020 Elsevier Inc. All rights reserved.