Novel plasmonic Bi nanoparticles deposited in situ in (BiO)2CO3 microspheres (Bi/BOC) were fabricated via a one-pot hydrothermal treatment of bismuth citrate, sodium carbonate, and thiourea. Different characterization techniques, including XRD, SEM, TEM, XPS, UV–vis DRS, PL, time-resolved fluorescence spectra, and photocurrent generation, were performed to investigate the structural and optical properties of the as-prepared samples. The results indicated that the Bi nanoparticles were generated on the surface of (BiO)2CO3 microspheres via the in situ reduction of Bi3+ by thiourea. The Bi nanoparticle deposited (BiO)2CO3 microspheres were employed for the photocatalytic removal of NO in air under visible light irradiation, and the sample exhibited a drastically enhanced photocatalytic activity and oxidation ability. The highly enhanced activity was attributed to the cooperative contribution of the surface plasmon resonance (SPR) effect, the efficient separation of electron–hole pairs, and the prolonged lif...