The present work describe the synthesis of Cd 0.9 Zn 0.1 S and Cd 0.87 Zn 0.1 Ni 0.03 S nanostructures by chemical co-precipitation method. The XRD profile proved the cubic crystal structure of the samples without any impurity related phases. The reduced size from 63 to 51 Å and the dissimilarities in lattice parameters and micro-strain has been discussed by Ni addition in Cd 0.87 Zn 0.1 Ni 0.03 S structure. The noticed anomalous optical studies and the elevated transmittance at Ni doped sample suggested them for the fabrication of efficient opto-electronic devices. The energy gap reduction during the substitution of Ni = 3% is explained by the generation of extra energy levels associated with defects within the two bands. The release of additional charge carriers, improved optical property, reduced particle size and more defect generation are responsible for the enhanced photo-catalytic performance of Ni doped Cd 0.9 Zn 0.1 S. The enhanced anti-bacterial capacity in Cd 0.87 Zn 0.1 Ni 0.03 S is described by the collective response of reduced particle size and higher reactive oxygen species (ROS) like O 2 ⋅− , H 2 O 2 and OH ⋅ generating capacity.