ZIF-8 derived porous C, N co-doped ZnO modified B-g-C3N4: A Z-Scheme charge dynamics approach operative towards photocatalytic hydrogen evolution and ciprofloxacin degradation

Abstract

Herein, the fabrication of a robust CNZ/BCN nanocomposite is achieved by a facile in-situ calcination of ZIF-8 along with BCN precursors. Morphologically the dodecahedral ZIF-8 farmeworks are transformed into granular CNZ nanoparticles that were densely adhered to the BCN nanosheet surface with interfacial interactions. MOF derived strategy plays significant role in reducing the optical band gap via introducing C, N into the ZnO lattice as known from UV–vis-DRS as well as XPS studies. Additionally the composite formation lead to significantly enhanced exciton anti-recombination as suggested from EIS and PL analysis. The optimal CNZ/BCN (1:1) nanohybrid exhibits enhanced photocatalytic H2 evolution rate of 7020 µmol h−1 g−1 which is nearly-two and eight folds greater than that of pristine CNZ and BCN respectively along with maximal ciprofloxacin photo-degradation rate (86.7 %). The radical trapping experiments deduced the formation of both superoxide and hydroxyl radicals that promotes the nanocomposite to follow Z-scheme charge transfer pathway during photocatalysis. Intermediates formed during CIP photo-degradation were identified by using LC-MS technique that showed ten intermediates formed through two different routes. Hence, MOF derived CNZ and BCN nanocomposite acts as a robust Z-scheme mediated photocatlyst that can be employed for varied energy and environmental purposes.