Unraveling Precise Locations of Indium Atoms in g‐C₃N₄ for Ameliorating Hydrogen Peroxide Piezo‐Photogeneration

Abstract

Increasing active sites in catalysts is of utmost importance for catalytic processes. In this regime, single‐atom dispersing on graphitic carbon nitrides (g‐C3N4) to produce fine chemicals, such as hydrogen peroxide (H2O2), is of current interest due to not only enhancing catalytic performance but also reducing the loading of necessary metals. Hence, we, in this research, engineered g‐C3N4 by atomically dispersing aluminum (Al) or indium (In) sites to provide catalytic active centers via one‐step thermal shock polymerization. The addition of Al and In sites can accelerate the catalytic efficacy owing to the Lewis acid‐base interactions between these metals and oxygen (O2). Under catalytic conditions, the formation of oxygenic radicals would strongly be associated with the enhanced formation of H2O2, confirmed by in‐situ electron paramagnetic resonance (EPR) spectroscopy. Furthermore, the empirical analyses from positron annihilation spectroscopy (PAS) show that In atoms would occupy the near positions of carbon vacancies (VC) to form N‐VC@In‐O bonds. This replacement would produce the highest formation energy based on the density functional theory (DFT) calculations, improving the stability of atom‐dispersive materials. Therefore, via the combination of experimental and theoretical proofs, this study suggests the exact location of In atoms in g‐C3N4 structures, which can help boost the catalytic production of H2O2.This article is protected by copyright. All rights reserved.

Promoted Hydrogen Peroxide Production from Pure Water on g-C3N4 with Nitrogen Defects Constructed through Solvent-Precursor Interactions: Exploring A Complex Story in Piezo-Photocatalysis

“…S20 to roughly estimate the fraction of defects in the materials. Three deconvoluted peaks at around 437, 456, and 494 nm, corresponding to 2.84, 2.72, and 2.51 eV, as normally observed [32]. The additional peaks in the PL deconvoluted spectra would demonstrate the defective states in the optical bandgap of the materials caused by the cooperation of nitrogen vacancies in different locations [13].…”

“…were recorded for all studied samples. Here, τ1 was attributed to the combined annihilations of the positron in perfect structure and monovacancies (Nv or Cv), while τ2 was associated with vacancy clusters of Nv + Cv [24,32,33]. Fig.…”

Promoting Proton Donation through Hydrogen Bond Breaking on Carbon Nitride for Enhanced H2O2 Photosynthesis

“…The active sites might be attacked by hot electrons, hot holes, and reactive oxygen species, such as hydroxyl radicals. 42 Moreover, the mass loss caused by centrifugation after each cycle can also lead to the decrease in the photocatalytic activity. The photostationary concentration of H 2 O 2 is known to be determined by the competition between the formation rate (k f ) and decomposition rate (k d ) of H 2 O 2 over the catalyst.…”

A Direct Z-Scheme Single-Atom MOC/COF Piezo-Photocatalytic System for Overall Water Splitting

“…H 2 is a clean secondary energy source with advantages such as high calorific value and a nonpolluting combustion process, making it the new energy source of choice for the 21st century. H 2 O 2 serves as an environmentally friendly chemical oxidant and a promising energy carrier with widespread applications in a variety of fields, including medicine, industry, and the environment . The key to achieving high photochemical conversion is the development of suitable photocatalysts .…”

“…H 2 O 2 serves as an environmentally friendly chemical oxidant and a promising energy carrier with widespread applications in a variety of fields, including medicine, industry, and the environment. 1 The key to achieving high photochemical conversion is the development of suitable photocatalysts. 2 Robust light absorption capacity, appropriate optical band gap and band position alignments, coupled with effective carrier mobility and reduced electron−hole recombination, are critical factors for highly efficient photocatalysts.…”