Solar disinfection (SODIS), as a point-of-use (POU) water disinfection strategy for controlling waterborne microorganisms, serves millions of residents daily in over 50 low- to middle-income countries lacking basic drinking water services. However, SODIS is time consuming (6-48 h of sunlight exposure) due to its strong dependence on UV photons, which account for only ~4% of the solar energy. Thus, it is desirable to capture additional energy from visible-light photons (~50% of the solar energy) to accelerate the slow kinetics. Here, we use phosphorene nanoflakes (PNs) and BiOI nanosheets (BS) as model materials to construct a heterojunction photocatalyst, illustrating that simultaneously modulating the interfacial interaction and band alignment between the heterojunction components can achieve a dual optimization of the kinetic and thermodynamic constraints in photo-induced charge carriers, effectively enhancing the utilization of visible-spectrum energy for microbial inactivation. Notably, a subminute photocatalytic water disinfection performance is demonstrated by the PNs/BS heterojunction, completely inactivating 7 log of E. coli within 45 s under real sunlight. This results in a first-order disinfection rate ~221 times greater than that of commercial P25 TiO2. This work provides insights into the design of potent antimicrobial photocatalysts for POU water disinfection applications.
He et al. (2026) studied this question.