In Situ Construction of Ag/TiO2/g-C3N4 Heterojunction Nanocomposite Based on Hierarchical Co-Assembly with Sustainable Hydrogen Evolution

摘要

The construction of heterojunctions provides a promising strategy to improve photocatalytic hydrogen evolution. However, how to fabricate a nanoscale TiO /g-C N heterostructure and hinder the aggregation of bulk g-C N using simple methods remains a challenge. In this work, we use a simple in situ construction method to design a heterojunction model based on molecular self-assembly, which uses a small molecule matrix for self-integration, including coordination donors (AgNO ), inorganic titanium source (Ti(SO ) ) and g-C N precursor (melamine). The self-assembled porous g-C N nanotube can hamper carrier aggregation and it provides numerous catalytic active sites, mainly via the coordination of Ag ions. Meanwhile, the TiO NPs are easily mineralized on the nanotube template in dispersive distribution to form a heterostructure via an N–Ti bond of protonation, which contributes to shortening the interfacial carrier transport, resulting in enhanced electron-hole pairs separation. Originating from all of the above synergistic effects, the obtained Ag/TiO /g-C N heterogenous photocatalysts exhibit an enhanced H evolution rate with excellent sustainability 20.6-fold-over pure g-C N . Our report provides a feasible and simple strategy to fabricate a nanoscale heterojunction incorporating g-C N , and has great potential in environmental protection and water splitting.