Controlled Synthesis of Nitro-Terminated Poly[2-(3-thienyl)-ethanol]/g-C₃N₄ Nanosheet Heterojunctions for Efficient Visible-Light Photocatalytic Hydrogen Evolution

Abstract

Exploration of closely contacted polymeric nanoheterojunctions with suitable frontier molecular orbital energy levels is highly desired for promoting the carrier separation and further improving the photocatalytic performance. In our work, poly [2-(3-thienyl)ethanol]/g-C 3 N 4 (PTEtOH/g-C 3 N 4 ) nanosheet heterojunctions were successfully fabricated using a controlled surface hydroxyl-induced assembly process and displayed obviously improved visible-light performance for H 2 evolution. As verified by time-resolved photoluminescence spectra, surface photovoltage spectra and •OH amount measurements, the improved performance is due to the promoted photogenerated carrier transfer and separation in the synthesized PTEtOH/g-C 3 N 4 heterojunction with strengthened interface contacts via hydrogen bonding. Furthermore, single-wavelength photocurrent action spectra were performed to confirm that the promoted photogenerated carrier separation is mainly dependent on the excited high-level electron transfer from g-C 3 N 4 to PTEtOH. Interestingly, the photocatalytic performance is further improved by synthesizing nitro-terminated PTEtOH (N-PTEtOH) with lowered LUMO energy level and decreased particle size and then constructing N-PTEtOH/g-C 3 N 4 nanosheet heterojunction, exhibiting a factor-of-15 enhancement, in comparison with that of g-C 3 N 4 and obvious superiority to reported photoactivities. Noteworthily, abundant hydroxyl groups on the surface of the heterojunctions are beneficial for the uniform deposition of Pt nanoparticles as co-catalysts and hence for photocatalytic reactions. This study offers a feasible strategy to design efficient polymeric heterojunctions as nanophotocatalysts for solar-lightdriven energy production.

A well-defined S-g-C3N4/Cu–NiS heterojunction interface towards enhanced spatial charge separation with excellent photocatalytic ability: synergetic effect, kinetics, antibacterial activity, and mechanism insights

“…g-C 3 N 4 has gained excessive research consideration as a probable photocatalyst by scientists for a variety of applications. [20][21][22][23] It has various features necessary for photocatalysis reactions such as being non-toxic, chemically and thermally stable and visible light-responsive. 24 Similarly, due to the quick recombination of e À and h + couples, the photocatalytic activity of undoped g-C 3 N 4 is limited.…”

Rational Construction of Z‐Scheme Charge Transfer Based on 2D Graphdiyne (g‐CnH2n−2) Coupling with Amorphous Co3O4 Quantum Dots for Efficient Photocatalytic Hydrogen Generation

“…[ 68 ] Moreover, the bandgap value for GDY and CQDs are calculated by the Tauc equation: αhν = A ( hν − E g ) n /2 (wherein α is the absorption coefficient, hν is the photo energy and n is dependent on the transition type of catalysts). [ 69 ] The bandgap values for GDY and CQDs are 1.39 and 1.58 eV, respectively.…”

Highly crystalline sulfur and oxygen co-doped g-C3N4 nanosheets as an advanced photocatalyst for efficient hydrogen generation

“…[14][15][16] Therefore, it is urgent to develop a modified g-C 3 N 4 photocatalyst for improving the conversion efficiency of solar energy to chemical energy. So far, a variety of effective strategies, including heterojunction fabrication, [17][18][19] morphology tailoring, [20][21][22] and heteroatom doping, [23][24][25] have been developed to promote the photocatalytic hydrogen production of g-C 3 N 4 . Among all the doping elements, nonmetal oxygen doped g-C 3 N 4 is one of the effective ways to extend the visible-light absorption and regulate the intrinsic electronic characteristics and band structure of g-C 3 N 4 , thereby leading to an enhancement of its photocatalytic activities.…”