A polydiacetylene-based smart cellulose aerogel functionalized by ZnO/MoS2 heterojunction for simultaneous visual detection and photocatalytic degradation of gaseous VOCs

The integration of visual detection and degradation of volatile organic compounds (VOCs) is greatly desired for addressing ever-growing environmental problems. Herein, a chemically cross-linked cellulose aerogel is explored as substrate material, combing with ZIF-8/MoS2 derived 2D ZnO/MoS2 heterojunction. Then polydiacetylene (PDA) was self-assembled on the aerogel via topochemical polymerization to obtain a smart gas sensing and eliminating hybrid aerogel (PZMCA) with high porosity (>96%). The intrinsic stimulate responsiveness and the flower-like hierarchical structure of PDA contributed to a sensitive and fast color response to gaseous toluene with 10 s. Moreover, by regulating the mass ratio of ZnO and MoS2, the PZMCA presented enhanced photocatalytic ability for toluene (97% of degradation efficiency with 180 min) under solar light irradiation. GC-MS reveals the possible mechanism and pathway of the photocatalytic degradation of toluene. The robust, uniform, versatile and functional aerogels could hopefully provide practical applications in VOCs detection and photocatalytic degradation.