Selective Cocatalyst Decoration of Narrow‐Bandgap Broken‐Gap Heterojunction for Directional Charge Transfer and High Photocatalytic Properties

Abstract

Narrow‐bandgap semiconductors are promising photocatalysts facing the challenges of low photoredox potentials and high carrier recombination. Here, a broken‐gap heterojunction Bi/Bi2S3/Bi/MnO2/MnOx, composed of narrow‐bandgap semiconductors, is selectively decorated by Bi, MnOx nanodots (NDs) to achieve robust photoredox ability. The Bi NDs insertion at the Bi2S3/MnO2 interface induces a vertical carrier migration to realize sufficient photoredox potentials to produce O2•− and •OH active species. The surface decoration of Bi2S3/Bi/MnO2 by Bi and MnOx cocatalysts drives electrons and holes in opposite directions for optimal photogenerated charge separation. The selective cocatalysts decoration realizes synergistic surface and bulk phase carrier separation. Density functional theory (DFT) calculation suggests that Bi and MnOx NDs act as active sites enhancing the absorption and reactants activation. The decorated broken‐gap heterojunction demonstrates excellent performance for full‐light driving organic pollution degradation with great commercial application potential.

Structure‐Function Relationship of p‐Block Bismuth for Selective Photocatalytic CO2 Reduction

“…We used a strategy as in situ partially thermal reducing oxygen vacancy of Bi 2 MoO 6 ‐V O to prepare adjacent V O /Bi heterosites (Bi 2 MoO 6 ‐V O /Bi) (Figure 1a). Firstly, the Bi 2 MoO 6 ‐V O was prepared through a hydrothermal method using ethylene glycol as the reductant to create oxygen vacancies [30] . These oxygen vacancies were then partially reduced to metallic Bi by precisely controlling the H 2 thermal reduction condition, resulting in the formation of V O /Bi heterosites (Figure S1).…”

Slow Photonic Effect Inducing Improved H2 Generation in Photonic Films with Chiral Nematic Structure

“…These strategies can be broadly categorized into two main approaches: expanding the semiconductor's optical response across a wider spectral range and improving light–matter interactions. In the former approach, techniques such as doping with non‐metallic ions [ 2–4 ] or transition metal cations, [ 5,6 ] incorporating noble metal nanoparticles, [ 7,8 ] sensitizing the semiconductor's, [ 7,9,10 ] and constructing heterojunction [ 11–14 ] have shown effectiveness. However, they face various challenges, including stability issues, increased recombination of charge carriers, weakened redox ability, selectivity, high costs, and toxicity concerns.…”

Unraveling the role of surface and interfacial defects in hydrogen production to construct an all-in-one broken-gap photocatalyst

“…4,5 However, improving all these complex and multiple properties in one semiconductor photocatalyst remains an enormous challenge. Traditional strategies involve doping, 6,7 metal loading, [8][9][10] or coupling with another semiconductors [11][12][13] to promote or suppress specic steps at the expense of lower overall stability or performance. Researchers have addressed these issues through the construction of heterojunctions using semiconductors with suitable potential energies, which allow interfacial charge separation through different schemes (e.g.…”

“…The non-overlap bandgap was considered a barrier to optimizing carrier migration and separation; fortunately, type B heterojunctions (Bi/Bi 2 S 3 /Bi/MnO 2 /MnO x , WO 3 /Ag/GdCrO 3 , Ag 3 PO 4 / Ag/GdCrO 3 , and WO 3−x /GdCrO 3 ) constructed from broken-gap type III heterostructures have recently been identied as a robust catalyst for volatile organic compound (VOC) degradation. 8,14,22,23 Plasmonic nanoparticles (e.g. Ag and Bi) or semiconductors (e.g.…”

“…WO 3−x ) were identied as a bridge favoring carrier transfer and improving the photocatalytic performances. 8,14,22,23 In general, the interface of two semiconductors ensures contact and electron ow during the activation process of multicomponent heterojunctions. However, this interface has been overlooked for broken-gap heterojunctions, and an investigation into the relationship between interfacial charge transfer, light absorption, and surface reaction is needed.…”