A dual polymer composite of poly(3-hexylthiophene) and poly(3,4-ethylenedioxythiophene) hybrid surface heterojunction with g-C(3)N(4) for enhanced photocatalytic hydrogen evolution

A surface heterojunction catalyst of g-C(3)N(4)–PEDOT/P3HT with P3HT and PEDOT as the polymer sensitizer and hole transport pathway is successfully prepared. The as constructed g-C(3)N(4)–PEDOT/P3HT composite exhibits a photocatalyst H(2) evolution rate up to 427703.3 μmol h(−1) g(−1) which is 1059 times higher than that of g-C(3)N(4), 118 times higher than that of g-C(3)N(4)–PEDOT with ascorbic acid as sacrificial reagents. What's more, the g-C(3)N(4)–PEDOT/P3HT can even show an obviously enhanced photocatalytic H(2) evolution rate which is 6.1 times higher than that of pure g-C(3)N(4) in pure water without any sacrificial reagent. Combining the experimental results and molecular dynamic (MD) simulation results, a possible mechanism can be drawn that the existed PEDOT possesses relatively higher hole mobility and can be used as a hole conductor between g-C(3)N(4) and P3HT. Then, the photogenerated holes migration can be accelerated by PEDOT from the VB of g-C(3)N(4) to the VB of P3HT. All those factors may benefit the synergy among g-C(3)N(4), PEDOT and P3HT, which finally facilitates the rapid migration of photoinduced electron–hole pairs and eventually improves the photocatalytic H(2) activity process of g-C(3)N(4)–PEDOT/P3HT with visible light. The present work may provide useful insights for designing a surface heterojunction composite photocatalyst with high photocatalytic activity for H(2) production.