Rational Design of Lead-Free CsCu2I3@g-C3N4 Composite for Efficient Energy Storage and Sustainable Catalysis

Abstract

Rationally constructed lead-free halide perovskite-based composite provides an effective approach for upgrading their many unique physicochemical properties. In this work, we report the design and synthesis of a stable lead-free CsCu2I3 (CCI) perovskite integrated with g-C3N4 (CN) by employing a simple ultrasonication approach. The individual components, CsCu₂I₃ and g-C3N4, were synthesized separately using the hot-injection method and thermal polycondensation method, respectively. Interestingly, the composite material CsCu2I3@g-C3N4 (CCI-CN) exhibited an outstanding hybrid supercapacitive behaviour and opens up a new avenue for the unaccustomed electrochemical potential of Cu-based lead-free halide perovskite. Hybrid CCI-CN material was also examined for the first time as a heterogeneous multifunctional catalyst in the photo-hydration of benzonitrile, and photo-reduction of para-nitroaniline. Moreover, the synthesized composite catalyst is very efficient for the synthesis of medicinally potent N-heterocyclic compounds, quinazolin-4(3H)-one moieties. It has been observed that CsCu2I3@g-C3N4 not only outperforms its individual components, CsCu2I3 and g-C3N4 but also surpasses other reported catalysts for the aforementioned transformations, delivering excellent product yields. This can be attributed to the cooperation and synergistic effects of the CsCu2I3 and g-C3N4 heterojunction. Photoluminescence studies reveal the reduced recombination of composite material providing a fast channel for the transfer of photogenerated electrons with lesser PL lifetime of CCI-CN (119.8307 ns) than CCI (151.2798 ns). Hence, this study provides an idea and opportunities of Cu-based halide perovskite composite as efficient material for charge storage and versatile catalytic activity.