A simple low-cost one-pot photodeposition synthesis with no hazardous reactants or products is used to make silver nanoparticles-activated carbon composite (SNPs@AC). The SNPs are homogenously and photodeposited and absorbed into the activated carbon matrix. Both SNPs and SNPs@AC composite have particle sizes around 10 nm and 100 nm, respectively. The SNPs@AC composite showed good antiviral activity to VERO (ATCC ccl-81) cells. Zeta potential of SNPs@AC composite is −25 mV, showing that this colloidal system is electrically stable and resistant to coagulation. For many Gram-positive and Gram-negative bacteria, the SNPs@AC composite demonstrated strong antibacterial efficacy. The SNPs@AC composite has 75.72 percent anti-inflammatory effect at concentration 500 µg/mL. This composite has a maximum non-toxic concentration (MNTC) of 78.125 g/mL, which corresponds to antiviral activity of up to 96.7 percent against hepatitis A. virus (HAV). It is suggested as a candidate for pharmaceutical formulations, such as integration into the manufacture of N95 masks for COVID-19 infection protection. Concentration 160 μg/mL SNPs@AC composite has antioxidant activity 42.74% percent. The SNPs@AC composite exhibited selective catalytic activity for the organosynthesis hydrazination reaction of 4-chloro-3, 5-di-nitro-benzo-triflouride, giving 1-hydroxy-4-nitro-6-trifluoro-methyl benzotriazole, a common antiviral drug for severe acute respiratory syndrome (SARS). SNPs@composite's well-defined pores provide suitable active sites for binding reactants: 4-Cl-3, 5-di-NO2-benzotriflouride, and hydrazine, which react to create 1-hydroxy-4-nitro-6-trifluoromethyl benzotriazole, which diffuses into solution away from the catalyst surface, leaving the catalyst surface unaffected.