ZnS nanoparticles were prepared on the surface of polyacrylonitrile (PAN) and methyl methacrylate (MMA)/butyl methacrylate (BMA)/acrylic acid (AA) copolymer nanofibers. The MMA-BMA-AA copolymer was synthesized by bulk radical polymerization using 2,2'-azobisisobutyronitrile as the initiator. The PAN and MMA-BMA-AA copolymer nanofibers were prepared by electrospinning. Zinc ions were introduced onto the surface of the nanofibers by coordination with the carboxyl of AA. Then, sulfide ions were added to react with zinc ions to form ZnS nanoparticles. The average diameter of the nanofibers was about 300 nm, and the diameter of the ZnS nanoparticles was about 10 nm. The band position of the photoluminescence spectrum of the ZnS/PAN and MMA-BMA-AA nanocomposites had an 80-nm blueshift in comparison with that of the corresponding bulk ZnS sample. The ZnS/PAN and MMA-BMA-AA nanocomposites had high photocatalytic activity for the degradation of phenol under ultraviolet irradiation; the photocatalytic activity changed indistinctively after it was used repeatedly (6 times). The nanofibers of PAN and MMA-BMA-AA not only dispersed but also stabilized the ZnS nanoparticles. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1264-1269,2009