•Ag/rGO was successfully synthesized by co-precipitation.•L-ascorbic acid (environmentally friendly and abundant) was used as the reducing agent.•AgNPs with size 16 ± 3.7 nm were decorated on rGO.•Amount of reducing agents and catalysts, reaction time and type of dye significantly affect the antibacterial activity.•Ag/rGO effectively inhibited the development of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The present study involved the preparation of silver-reduced graphene oxide (Ag/rGO) using co-precipitation method. The characteristics of Ag/rGO were confirmed by X-ray Diffraction patterns, Fourier transformation infrared spectroscopy, Raman spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller specific surface area, scanning electron microscopy, and energy-dispersive spectroscopy. The results demonstrated that silver nanoparticles (AgNPs) having diameter of 16 ± 3.7 nm were uniformly integrated on reduced graphene oxide (rGO) The as-synthesized Ag/rGO had a specific area of 54m2/g and 67.36 wt% silver. Antibacterial and catalytic properties of Ag/rGO were then further investigated. Ag/rGO was found to effectively inhibit the developing of gram-negative and gram-positive bacteria such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa with the bactericidal rates of 89.35, 95.67, and 99.99 %, respectively. In addition, the catalytic property of Ag/rGO in the reduction of organic dyes was tested with different dosage of reducing agent, amount of catalyst, type of dye, and reaction time. More than 99 % of dyes in aqueous solution at 20 mg/L concentration were reduced after 30 min with amounts of Ag/rGO and sodium borohydride of 10 and 30 mg successively. All results confirmed the potential application of Ag/rGO in the treatment of infected water and dye contamination.