Synthesis of efficient TiO2/Al2O3@Cu(BDC) composite for water splitting and photodegradation of methylene blue

Development of an efficient photocatalyst for the water splitting to fulfill the increasing energy demands of world and degradation of organic pollutant in water especially methylene blue to make it safe for aquatic life is a great challenge. In this reported article, an efficient and novel photocatalyst TiO2/Al2O3@Cu(BDC) has been synthesized by in situ incorporation of pre-synthesized precursors into Cu(BDC). It shows maximum activity towards water splitting for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Similarly, it shows maximum activity for photodegradation of methylene blue as compared to all other synthesized samples. Results showed that this novel TiO2/Al2O3@Cu(BDC) composite exhibits increase charge separation and better photocatalytic activity as compared to precursors. It is observed that maximum photocatalytic activity of TiO2/Al2O3@Cu(BDC) is mainly due to successful formation of hetro-junction between TiO2/Al2O3 and Cu(BDC) and reduce of electron-hole pair recombination. Under irradiation of visible light, photoexcited electrons are transferred from conduction band of Cu(BDC) to conduction band of TiO2/Al2O3 and further these photoexcited electrons form the O2•− and •OH radicals at surface of photocatalyst, which directly degrade the methylene blue. On the other side at valance band of Cu(BDC), positive hole (h+) forms the •OH radicals and degraded the methylene blue. This study encourages the development of more efficient MOFs based photocatalyst and used in photocatalytic applications.