Dopamine Modified g-C₃N₄ and Its Enhanced Visible-Light Photocatalytic H₂-Production Activity

Abstract

Photocatalytic water splitting is a promising strategy to convert solar energy into chemical energy. Herein, a series of g-C3N4/polydopamine (g-C3N4/PDA) composites were successfully fabricated by in situ polymerization of dopamine on the g-C3N4 surface. Among all the as-prepared composites, the best photocatalytic hydrogen evolution rate of the as-prepared composites was up to 69 μmol h–1 under the irradiation of visible light (λ > 420 nm), which was about 4.5 times than that of pristine g-C3N4 (16 μmol h–1). The enhancement of photocatalytic H2 evolution is reasonably attributed to the markedly enhanced light harvesting, broadened spectral response range and low onset potential of H2 production, as well as effective separation and rapid transportation of photogenerated charge carriers. More importantly, the surface modification of g-C3N4 by a small amount of PDA can effectively inhibit the overgrowth of Pt nanoparticles (NPs) during the photocatalytic reactions, which promotes the photoelectron injection and better photocatalytic activity. This work should provide a new insight into preparing metal-free polymer–polymer composites with effective solar energy conversion.

Unraveling Photoexcited Charge Transfer Pathway and Process of CdS/Graphene Nanoribbon Composites toward Visible‐Light Photocatalytic Hydrogen Evolution

“…Figure a shows nitrogen adsorption–desorption isotherms and the corresponding pore‐size distribution curves of CdS, CdS/GNR2, and CdS/GNR10 samples. All of them exhibit type IV isotherm with typical H3 hysteresis loops in the relative pressure range of 0.4–1.0 based on the International Union of Pure and Applied Chemistry (IUPAC) and Brunauer–Deming–Demin–Teller classification, indicating the presence of mesoporous structure in the samples. The pore size distribution of CdS, CdS/GNR2, and CdS/GNR10 ranges from 2 to 100 nm and the center locates at ≈10 nm (inset in Figure a).…”

3D Graphene‐Based H2‐Production Photocatalyst and Electrocatalyst

“…So far, many strategies have been developed to improve the light absorption ability of photocatalysts including surface modification, heteroatom doping, plasmonic metal deposition and so on. [ 99–104 ] In particular, compositing the semiconductor with carbonaceous motifs (such as graphene, [ 16 ] graphdiyne, [ 105 ] amorphous carbon, [ 106 ] MXene, [ 107 ] etc.) has been recognized to significantly improve the light absorption efficiency owing to their black color characteristic.…”

Enhanced Light‐Driven Hydrogen‐Production Activity Induced by Accelerated Interfacial Charge Transfer in Donor–Acceptor Conjugated Polymers/TiO2 Hybrid

“…[21][22][23][24][25] Very recently,m edium-band gap conjugated polymers composedo fa lternating electron donor( D) and electron acceptor (A) have emerged as promising photocatalysts. [26][27][28][29][30][31][32][33][34][35][36] In contrastt og -C 3 N 4 and often used conjugated polymers formed by polymerization of same chemical units, such as polydopamine (PDA), [37][38] poly-3-hexylthiophene( P3HT), [39][40] polypyrrole (PPy), [41] and polyaniline (PANI), [42][43] the energyl evels of the D-A conjugated polymers can be facilely tuned by optimizing chemical structures of Do r Au nits for superior photocatalytic H 2 evolution rate (HER). [44][45] We previouslyc onstructed D-A conjugated based heterojunctions by in situ polycondensation and significantly enhanced their photocatalytic activity.…”