Supramolecule self-assembly synthesis of condensed C-TA/g-C3N4 composites for promoting charge transfer and photocatalytic H2 evolution

Abstract

Design of highly condensed g-C3N4 is a prospective way to optimize the photoreactivity of g-C3N4 as it possesses condensed structure with decreased interlayer spacing, which benefits both charge transfer and light harvesting. Herein, we report that novel condensed carbonized-tannic acid (C-TA)/g-C3N4 composites have been acquired via a supramolecular self-assembly of TA and melamine into TA/melamine precursors followed by thermal condensation. The acquired condensed C-TA/g-C3N4 composites present superior visible-light photocatalytic activity for H2 evolution. The 1 wt% C-TA/g-C3N4 composite shows 4.2 times enhancement of photocatalytic activity for H2 evolution compared to pristine g-C3N4. The TA with distinct adhesion properties and functional groups of OH, which is firmly linked with melamine, can confine the melamine inside to promote the condensation to gain more condensed g-C3N4. The condensed C-TA/g-C3N4 composites with decreased interlayer distance effectively promote charge transfer and photocatalytic H2 evolution.