Nitrogen Defects-Rich 0D/2D α-Fe₂O₃/g-C₃N₄ Z-Scheme Photocatalyst for Enhanced Photooxidation and H₂ Evolution Efficiencies

Abstract

Rational design and construction of Z-scheme photocatalysts have received much attention in the fields of organic pollutants degradation and H2 evolution because of their potentials to solve the current environmental and energy crises. Herein, a novel nitrogen defects-rich 0D/2D [Formula: see text]-Fe2O3/g-C3N4 Z-scheme photocatalyst was fabricated via a one-pot co-pyrolysis method. Quantum-sized [Formula: see text]-Fe2O3 dots with a diameter of approximately 5[Formula: see text]nm were uniformly distributed on the surface of 2D g-C3N4. Besides, the prepared 0D/2D [Formula: see text]-Fe2O3/g-C3N4 composites exhibited excellent RhB degradation ability and simultaneous H2 evolution efficiency. In comparison with 2D g-C3N4, the RhB degradation rate and H2 evolution catalyzed by 0D/2D [Formula: see text]-Fe2O3/g-C3N4 were enhanced 3.9 and 1.8 times, respectively. The improved photoredox activity was predominantly attributed to the formation of the nitrogen defects and a Z-scheme heterojunction. This study provides novel insights into the design and fabrication of nitrogen defects-rich g-C3N4-based Z-scheme photocatalysts for the simultaneous environmental purification and H2 evolution.

Two‐step calcination synthesis of Z‐scheme α‐Fe2O3/few‐layer g‐C3N4 composite with enhanced hydrogen production and photodegradation under visible light

“…They are correlated to the vibration of Fe 3+ -O −2 bounds in tetrahedron FeO 4 and octahedron FeO 4 , respectively. [17,30,38] The peaks at 1,637 and 3,436 cm −1 are attributed to water on the surface of the photocatalyst. [20] X-ray photoelectron spectroscopy (XPS) measurements ( Figure 3) were carried out to investigate the chemical states of the surface composition in 2.95% α-Fe 2 O 3 /FL g-C 3 N 4 nanocomposites.…”

“…, amino groups (C─NH), and the charging effects in heterocycles, respectively. [17,30] The highresolution spectrum ( Figure 3c) of O 1s shows three peaks at 529.7, 531.9, and 533.1 eV, which are attributed to lattice oxygen, surface hydroxyl groups, and O═C, respectively. The calcination process of g-C 3 N 4 exposed to a large area of air is beneficial to the formation of C═O bonds at the edges.…”

“…[29] However, problems, including the low surface area of the as-prepared composite and the uncontrolled particle size and poor dispersion of Fe 2 O 3 , seriously restrict its photocatalytic activity. [28][29][30] Furthermore, although many aspects of the interfacial charge carrier dynamics of α-Fe 2 O 3 /g-C 3 N 4 heterostructures have been identified, certain kinetic aspects of the carrier transfer need further investigation. [31][32][33] In this study, a Z-type nanojunction architecture of α-Fe 2 O 3 /FL g-C 3 N 4 photocatalysts with powerful interfacial charge transfer is rationally designed, in which α-Fe 2 O 3 exposed the {102} and {104} facets.…”

Construction of Charring-Functional Polyheptanazine towards Improvements in Flame Retardants of Polyurethane

“…The X-ray photoelectron spectroscopy (XPS) analysis images of CN, PCN, and Co@PCN are given in Figure 3 , and the atomic percentages of these particles are listed in Table 1 . In the C 1s spectrum ( Figure 3 b) of CN, the peaks at 285.08 and 288.28 eV were attributed to the sp 2 graphitic carbon (C–C=C) and sp 2 -bonded carbon in the triazine rings (N–C=N), respectively [ 43 ]. CN has a lower area ratio of graphitic carbon than PCN, and C–O (289.48 eV) appeared.…”

Graphitic carbon nitride (g‐C3N4)‐based nanosized heteroarrays: Promising materials for photoelectrochemical water splitting

“…A lot of research has revealed that the PEC performance of α‐Fe 2 O 3 is closely related to its morphologies and sizes, meaning that construction of α‐Fe 2 O 3 nanoarrays can greatly enhance the PEC efficiency of α‐Fe 2 O 3 ‐based photoelectrodes 150‐152 . In addition, combining α‐Fe 2 O 3 and g‐C 3 N 4 to form the heterojunctions is also an effective way to improve the PEC performance thanking the increased separation efficiency of photogenerated electrons/holes 66,153 . On the basis of the above reasons, the fabrication of α‐Fe 2 O 3 /g‐C 3 N 4 heteroarray photoanodes could lead to breakthrough progress for water oxidation.…”