Mg−O‐Bridged Polypyrrole/g‐C₃N₄ Nanocomposites as Efficient Visible‐Light Catalysts for Hydrogen Evolution

Abstract

It is highly desired to improve the visible‐light activity of g‐C3N4 for H2 evolution by constructing closely contacted heterojunctions with conductive polymers. Herein, a polymer nanocomposite photocatalyst with high visible‐light activity is fabricated successfully by coupling nanosized polypyrrole (NPPy) particles onto g‐C3N4 nanosheets through a simple wet‐chemical process, and its visible‐light activity is improved further by constructing Mg−O bridges between the NPPy and g‐C3N4. The amount‐optimized bridged nanocomposite displays an approximately ninefold improvement in visible‐light activity compared with g‐C3N4. On the basis of transient‐state surface photovoltage responses, photoluminescence spectra, .OH amount evaluation, and photoelectrochemical curves, it is concluded that the exceptional photoactivity can be attributed to the significantly promoted charge transfer and separation along with visible photosensitization from NPPy. Interestingly, it is confirmed that the promoted charge separation depends mainly on the excited high‐level electron transfer from g‐C3N4 to NPPy by single‐wavelength photocurrent action spectra. This work provides a feasible strategy for designing polymer nano‐heterojunction photocatalysts with exceptional visible‐light activities.

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

“…In the FS measurement, the coumarin reacts with the generated •OH under irradiation to produce 7-hydroxyl-coumarin, which can emit obvious fluorescence. Thus, the stronger FS signal is in accord with the higher •OH amount, and then more efficient carrier separation Figure c exhibits the fluorescent intensity order of samples, agreeing with the aforementioned SS-SPS and PL results.…”

“…g-C 3 N 4 , a visible-light-driven polymer semiconductor photocatalyst, has drawn worldwide attention, because of its suitable energy gap (2.7 eV) and lowest unoccupied molecular orbital (LUMO) energy level (LUMO = −3.02 eV), unique two-dimensional (2D) π-conjugated structure, eminent physicochemical stability, facile synthesis, and functionalization from low-cost materials. − Nevertheless, the bare g-C 3 N 4 still suffers from the low efficiency of photogenerated carrier separation, short carrier lifetime and weak visible-light absorption region (λ < 460 nm), resulting in its unsatisfactory photocatalytic H 2 production activity . In order to solve these problems, the vast majority of research to date has focused on g-C 3 N 4 modification by nanostructure design, surface modification, − and heterojunction fabrication. − Among them, the heterojunction fabrication has been proved to be one of the most promising ways for the enhancement of spatial photogenerated carrier separation and the improvement of photocatalytic activity .…”

Porous Organic Polymers for Catalytic Conversion of Carbon Dioxide

“…designed CTF with special structure (sulfur bridge) and combined with SnS 2 to generate SnS 2 /S‐CTFs (Figure 15). [119] SnS 2 /S‐CTFs effectively promoted the separation of electron‐hole pairs, and enhanced the reduction efficiency of CO 2 and CH 4 under visible light reached 123.6 μmol g −1 h −1 and 43.4 μmol g −1 h −1 , respectively. In general, although there are a few reports about POPs combined with inorganic semiconductors used in CO 2 PRR, relatively excellent catalytic efficiency was achieved in this case.…”

“… The schematic diagram showing construction of SnS 2 /S‐CTFs (a) and the transfer of photogenerated carriers (b) [119] …”

Facile assembly and improved photocatalytic activity of a special cuprous oxide/copper fluoride heterojunction induced by graphene oxide

“…As an economical and environmentally friendly strategy, photocatalytic water splitting technology has attracted the attention of researchers because it can convert solar energy into conservable chemical fuels. 1,2 In this regard, photocatalysts based on semiconductors that can effectively collect and transform light energy are of most interest. 3,4 As an environmentally friendly and cheap semiconductor with a narrow band gap, cuprous oxide has potential applications in many fields including solar cells, gas sensors, lithium-ion battery and photocatalysis.…”