Nickel molybdate and graphitic carbon nitride–nickel molybdate hybrid (NiMoO4@g-C3N4) materials were effectively produced by hydrothermal and polymerization techniques to enhance photoelectrochemical and photocatalytic efficacy. X-ray diffraction (XRD) research validated the crystalline structure of nickel molybdate and the effective incorporation of graphitic carbon nitride without disrupting the host lattice. Morphological investigations utilizing scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that pristine NiMoO4 displayed uniform microspherical structures, whereas the hybrid material exhibited ultrathin sheet-like architectures, enhancing interfacial contact and promoting efficient charge transport. The elemental composition was verified by energy-dispersive X-ray spectroscopy (XPS). BET surface area measurements revealed a significant increase from 89.1 m2 g−1 for NiMoO₄ to 117.3 m2 g−1 for the NiMoO4@g-C3N4 composite, indicating improved accessibility of catalytically active sites. Photoelectrochemical investigations revealed that the NiMoO4@g-C3N4 photoanode attained an exceptional photo-conversion efficiency of 8.5 ± 0.02%, with a short-circuit current density (JSC) of 6.84 ± 0.21 mA cm−2, an open-circuit voltage (VOC) of 0.71 ± 0.02 V, and a fill factor (FF) of 0.57 ± 0.03, surpassing the Pt electrode, which demonstrated an efficiency of 6.2 ± 0.02% (JSC = 5.12 ± 0.18 mA cm−2, VOC = 0.64 ± 0.02 V, FF = 0.54 ± 0.02). The photocatalytic degradation of Rhodamine B achieved 45, 56, and 93% for g-C₃N₄, NiMoO₄, and g-C₃N₄/NiMoO₄, respectively, with apparent rate constants of 0.0067, 0.0098, and 0.0452 min−1. Electrochemical impedance spectroscopy and transient photo-dynamic response studies demonstrated less charge-transfer resistance and improved carrier separation in the hybrid system. The computed double-layer capacitance (Cdl) rose from 3.6 mF cm−1 for NiMoO₄ to 21.2 mF cm−2 for NiMoO4@g-C3N4, indicating enhanced interfacial charge storage capacity. The findings indicate that NiMoO4@g-C3N4 is a potential multifunctional material for effective photoelectrochemical and photocatalytic applications.

Interfacial Charge Transport in Graphitic Carbon Nitride–Nickel Molybdate Hybrids for Dye-Sensitized Solar Cells and Environmental Photocatalysis

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发表日期：

2026年5月9日

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S. Vadivel

摘要

Nickel molybdate and graphitic carbon nitride–nickel molybdate hybrid (NiMoO₄@g-C₃N₄) materials were effectively produced by hydrothermal and polymerization techniques to enhance photoelectrochemical and photocatalytic efficacy. X-ray diffraction (XRD) research validated the crystalline structure of nickel molybdate and the effective incorporation of graphitic carbon nitride without disrupting the host lattice. Morphological investigations utilizing scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that pristine NiMoO₄ displayed uniform microspherical structures, whereas the hybrid material exhibited ultrathin sheet-like architectures, enhancing interfacial contact and promoting efficient charge transport. The elemental composition was verified by energy-dispersive X-ray spectroscopy (XPS). BET surface area measurements revealed a significant increase from 89.1 m² g⁻¹ for NiMoO₄ to 117.3 m² g⁻¹ for the NiMoO₄@g-C₃N₄ composite, indicating improved accessibility of catalytically active sites. Photoelectrochemical investigations revealed that the NiMoO₄@g-C₃N₄ photoanode attained an exceptional photo-conversion efficiency of 8.5 ± 0.02%, with a short-circuit current density (J_SC) of 6.84 ± 0.21 mA cm⁻², an open-circuit voltage (V_OC) of 0.71 ± 0.02 V, and a fill factor (FF) of 0.57 ± 0.03, surpassing the Pt electrode, which demonstrated an efficiency of 6.2 ± 0.02% (JSC = 5.12 ± 0.18 mA cm⁻², V_OC = 0.64 ± 0.02 V, FF = 0.54 ± 0.02). The photocatalytic degradation of Rhodamine B achieved 45, 56, and 93% for g-C₃N₄, NiMoO₄, and g-C₃N₄/NiMoO₄, respectively, with apparent rate constants of 0.0067, 0.0098, and 0.0452 min⁻¹. Electrochemical impedance spectroscopy and transient photo-dynamic response studies demonstrated less charge-transfer resistance and improved carrier separation in the hybrid system. The computed double-layer capacitance (Cdl) rose from 3.6 mF cm⁻¹ for NiMoO₄ to 21.2 mF cm⁻² for NiMoO₄@g-C₃N₄, indicating enhanced interfacial charge storage capacity. The findings indicate that NiMoO₄@g-C₃N₄ is a potential multifunctional material for effective photoelectrochemical and photocatalytic applications.