Undoped and B/Sn-doped ZnO nanoparticles are successfully produced by a simple mechanochemical method, and are characterized by XRD, FTIR, EDX, SEM, XPS and BET techniques. The XRD studies reveal that the prepared nanoparticles possess the hexagonal wurtzite structure of ZnO. The presence of various functional groups (-OH, -CH, Zn-O) are observed by FTIR. It is clear from EDX analysis that B, Sn, Zn and O elements are present in the nanoparticles. SEM images confirm the relatively smooth surface of B/Sn-doped ZnO nanoparticles. XPS results indicate that B and Sn are successfully doped into ZnO matrix. The photocatalytic performances of undoped and B/Sn-doped ZnO nanoparticles are investigated for the degradation of aqueous solution of Rhodamine B (RhB) dye in natural sunlight irradiation. The photocatalytic degradation of RhB dye in 1 h with B/Sn-doped ZnO nanoparticle is about 70.2%, which is significantly enhanced compared with the undoped ZnO (51.8%).