Homologous chemiluminescence resonance energy transfer on the interface of WS2 quantum dots for monitoring photocatalytic H2O2 evaluation

Abstract

Water disinfection is a significant process in water treatment. As the widely used disinfection method, sodium hypochlorite (NaClO) disinfection has the potential carcinogenic risk because of its chloramine byproducts. Hence, the green and noncarcinogenic photocatalytic disinfection becomes a new favourite. In photocatalytic disinfection, H2O2 with long lifetime and lasting antibacterial property plays a principal role. Therefore, monitoring H2O2 in this process is imperative and challenging, which facilitated the development of efficient disinfection technique. Herein, a novel homologous chemiluminescence resonance energy transfer (CRET) on the interface of WS2 QDS was designed to amplify the chemiluminescence (CL) emission of NaClO-H2O2 system. Interestingly, energy donators and acceptors were originated from WS2 QDs in this CRET system. In detail, W (IV) on the interface of WS2 QDS were oxidized to W (VI) by NaClO, and then W (VI) combined with H2O2 to generate in-situ reactive peroxotungstate. The unstable peroxotungstate rapidly decomposed to singlet oxygen (1O2) and then dimerised to (1O2)2* (a dimer of singlet oxygen). WS2 QDS received the energy from (1O2)2* to produce strong luminescence. Based on this mechanism, a new platform for H2O2 determination with high selectivity and sensitivity was proposed and successfully applied to evaluate the photocatalytic properties of five two-dimensional materials by monitoring the photocatalytic H2O2 evolution. This work deepens the understanding of the excellent property of WS2 QDs. More constructively, it provides a novel idea for designing effective CRET and explores its potential application in photocatalytic research.