Carbon Vacancy Mediated Incorporation of Ti₃C₂ Quantum Dots in a 3D Inverse Opal g-C₃N₄ Schottky Junction Catalyst for Photocatalytic H₂O₂ Production

Abstract

Photocatalytic H2O2 production is an environmentally friendly and sustainable production technique. Here, we fabricate the Ti3C2 quantum dot-modified defective inverse opal g-C3N4 (TC/CN) via a facile electrostatic self-assembly method. The resultant catalysts greatly facilitate the photocatalytic H2O2 production. The optimum H2O2 yield on TC/CN-20 reaches 560.7 μmol L–1 h–1, which is 9.3 times higher than that of bulk CN under visible light irradiation. This enhancement is attributed to the direction-induced bonding between carbon vacancies in g-C3N4 and TCQDs. The formation of a Schottky junction in the interface further realizes spatial separation of electron and holes, effectively avoiding the recombination of the charge carriers at defect sites. Therefore, this work not only constructs a high-performance photocatalyst for H2O2 production with outstanding yield and long-term recyclability but also develops a direction-induced bonding synthetic method and explores the functionary mechanism of defect sites in the Schottky junction for photocatalytic H2O2 production.

Engineering a surface defect-rich Ti3C2 quantum dots/mesoporous C3N4 hollow nanosphere Schottky junction for efficient N2 photofixation

“…8 cm −1 was observed in the C–N stretching vibration of C 3 N 4 /r-Ti 3 C 2 QDs, which can be ascribed to the binding of r-Ti 3 C 2 QDs. 34 Moreover, compared with pure C 3 N 4 , the intensity of the tri- s -triazine units in C 3 N 4 /r-Ti 3 C 2 QDs decreased, which also reflects the introduction of r-Ti 3 C 2 QDs.…”

“…38 The Ti 2p spectrum is divided into five peaks (Fig. 3g), in which peaks at 457.2 eV and 462.4 eV correspond to Ti 4+ 2p 3/2 and Ti 4+ 2p 1/2 , 39 peaks at 454.6 and 460.8 eV are assigned to the Ti–C bond, 40 and the peak at 458.2 eV is ascribed to Ti 3+ species. 24,41 The above XPS results well confirmed the successful fabrication of C 3 N 4 /r-Ti 3 C 2 QDs.…”

Cd3(C3N3S3)2 Polymer/Sn Schottky Heterojunction for Broadband‐Solar Highly Selective Photocatalytic CO2 Reduction

“…[ 46 ] The Schottky barrier effect promotes the charge separation efficiency of Sn/CdTMT and prevents the migrating electrons from returning to CdTMT. [ 47 ] Finally, the electrons accumulated on the surface of Sn and the adsorbed CO 2 molecules undergo a reduction reaction and are converted into CO. [ 48 ]…”

Engineering the heterogeneous interfaces of inverse opals to boost charge transfer for efficient solar water splitting

“…Attempts have been made to deposit different photocatalytic components on the ''host'' to build various interfacial heterojunctions including type I heterojunctions, Schottkey junctions, and Ohmic junctions. These can promote photo-induced charge separation and transportation [17][18][19][20]. Some excellent nanostructures can be found in the literature with considerable improvement for PEC performance, such as CdS nanorod@SnO 2 nanobowl [21], Fe 2 O 3 nanorod@nanobowl [22], 3D g-C 3 N 4 /Ni(OH) 2 [23], WO 3 / BiVO 4 /Co-Pi inverse opal [24], and fluorine-doped tin oxide (FTO)/FTO-nanocrystal/TiO 2 inverse opal [25].…”