UVC-LED Disinfection Technology: Mainstream Waveband Characteristics, Applications and Challenges

Driven by the global demand for public health security, ultraviolet C light-emitting diode (UVC-LED) disinfection technology has emerged as a promising mercury-free alternative to conventional methods. Adopting a wavelength-based comparative framework, this review systematically synthesizes the disinfection characteristics of four mainstream UVC-LED wavelength bands (233 nm, 254 nm, 260–270 nm, and 270–280 nm), facilitating direct cross-band comparison of inactivation mechanisms, biosafety profiles, and practical applicability. Each band presents distinct trade-offs shaped by wavelength-dependent optical properties: 233 nm far-UVC offers favorable tissue safety via stratum corneum protein absorption but is significantly attenuated by organic loads; 254 nm, constrained by low external quantum efficiency (EQE), remains the least studied; 260–270 nm, overlapping with the nucleic acid absorption peak and lying within a relatively transparent spectral window in absorptive media, generally achieves the highest broad-spectrum inactivation efficiency; and 270–280 nm, the most mature in fabrication, delivers strong protein damage and irreversible DNA lesions with superior energy efficiency. Microbial sensitivity follows a pattern modulated by genomic and strain-level factors, while environmental matrices and carrier properties substantially attenuate disinfection efficacy, though process-assisted strategies can partially mitigate these effects. Despite progress toward municipal-scale deployment, wall-plug efficiency (WPE) remains substantially below that of conventional mercury lamps, and the feasibility of scenario-based wavelength selection is constrained by considerable heterogeneity in experimental parameters across studies. By critically examining these challenges and limitations, this review aims to provide a reference for the further development and broader application of UVC-LED disinfection technology.