Architecture and Kinetic Studies of Photocatalytic H₂O₂ Generation and H₂ Evolution through Regulation of Spatial Charge Transfer via Z-Scheme Path over a (001) Facet Engineered TiO₂@MXene/B-g-C₃N₄ Ternary Hybrid

Abstract

Spatial charge separation and migration are the critical shortcomings dominating the core energy conversion corridors of photocatalytic systems. Here, a biomimetic multi-interfacial architecture providing strong coupled interaction and rapid charge transmission for photostable and competent photocatalytic H2O2 production and H2 evolution is proposed. The triple-hybrid all-solid-state Z-scheme system was formed with the (001) facet exposed TiO2 nanosheets derived from MXene layers and B-g-C3N4 nanosheets (M/(001)TiO2@BCN) through an electrostatic self-assembly strategy with intimate electronic interaction due to Ti orbital modulation and proper stacking among the hybrids. The metallic and highly conductive MXene layers act as solid state electron mediators in the Z-scheme heterojunction that promote electron–hole separation and migration efficiency. Specifically, the MTBCN-12.5 composite provides optimum yield of H2O2 up to 1480.1 μmol h–1 g–1 and a H2 evolution rate of 408.4 μmol h–1 (with ACE 6.7%), which are 4 and 20 fold greater than the pristine BCN, respectively. The enhanced photocatalytic performance is systematically identified by the increased surface area, higher cathodic and anodic current densities of −1.01 and 2.27 mA cm–2, delayed charge recombination as supported by PL and EIS measurement, and excellent photostability. The Z-scheme charge transfer mechanism is validated by time-resolved photoluminescence (TRPL) analysis, cyclic voltametric analysis, and the radical trapping experiment as detected by PL analysis. This research marks a substantial advancement and establishes the foundation for future design ideas in accelerating charge transfer.

Photocatalytic activity towards antibiotic degradation and H2 evolution by development of a Z-scheme heterojunction constructed from 1T/2H-MoS2 nanoflowers embellished on BCN nanosheets

“…S3,† the MBCN-10 photocatalyst has an average lifetime ( τ avg ) of 1.5 ns which is shorter than that of 1T/2H-MoS 2 which has a τ avg of 3.7 ns due to the charge dynamics of the Z-scheme heterojunction. 53,54…”

“…S3, † the MBCN-10 photocatalyst has an average lifetime (τ avg ) of 1.5 ns which is shorter than that of 1T/2H-MoS 2 which has a τ avg of 3.7 ns due to the charge dynamics of the Z-scheme heterojunction. 53,54 UV-vis DRS. As the light absorption ability of a material has great relevance to its photocatalytic properties, the optical properties of the synthesized pristine and composite materials were established using UV-vis differential reflectance spectroscopy (DRS) analysis, as shown in Fig.…”

Carbonized Polymer Dots/Bi/β-Bi2O3 for Efficient Photosynthesis of H2O2 via Redox Dual Pathways

“…Four vibrational modes are shown in the Raman spectra of β-Bi 2 O 3 (Figure 3b). A 1 (1) (90 cm −1 ) and B 1 (123 cm −1 ) are attributed to the external vibrations of the Bi−O bond, while A 1 (2) (312 cm −1 ) and A 1 (3) (447 cm −1 ) belong to its internal vibrations. 39 In Bi 2 O 2 CO 3 , the peaks at 71 and 162 cm −1 are assigned to shifts in the Bi and O atoms, respectively.…”

Virtual Issue: Electrode Interfaces

“…Within this Virtual Issue, notable contributions shine a spotlight on (1) promising electrode materials and exploring a few of the diverse roles that interfaces play in various electrochemical applications, such as water splitting and gas evolution, − biosensors, − and supercapacitors; − (2) mechanistic studies that aim to deepen our fundamental understanding of the electrode/electrolyte interface; − and (3) new and exciting methods and technologies. − This comprehensive approach seeks to make substantial contributions to the fields of energy conversion, energy storage, and sensing.…”

“…Advances in the papers on photo- and electrocatalysis, water splitting, and gas evolution are diverse: enhanced spatial charge separation and migration, increased specific surface area, coupling effects between polymetallic transition-metal phosphides and oxides, metal–organic framework trap centers, layered porous nanohybrid multifunctional materials, synergies of strong interactions of heterointerfaces and hierarchical heterostructures, the impact of bubbles, acid–base equilibria in electrolytes for CO 2 electrochemical reduction and CO reoxidation, and oxygen vacancy enhancements in photoelectrochemical water splitting as well as active site identification for O 2 reduction. , …”