Which from following metal nanoparticle is used for coating the filter material that acts as effective bacterial disinfectant?

The metal nanoparticle used for coating filter material that acts as an effective bacterial disinfectant is silver.

Silver nanoparticles exhibit potent broad-spectrum antimicrobial activity through membrane disruption, metabolic interference, and reactive oxygen species generation. While nickel, gold, and copper nanoparticles show some antimicrobial properties, silver nanoparticles demonstrate superior efficacy and are the standard choice for bacterial disinfection in filtration applications.

The final result is $\boxed{B}$.