The photo-activated thermo/gas antimicrobial nanocomposite hydrogel, Gel/PDA@BNN6, is composed of the nitric oxide (NO) carrier N, N'-di-sec-butyl-N, N'-dinitroso-p-phenylenediamine (BNN6), photothermal (PTT) material polydopamine nanoparticles (PDA NPs), and methacrylate gelatin (GelMA). This hydrogel can release NO gas in a stable and controlled manner, generating a localized photothermal effect when exposed to near-infrared laser light. This dual action promotes the healing of full-thickness skin wounds that are infected.