Abstract

The present study addresses a successful attempt to promote the photocatalytic reduction of mercury ions (Hg²⁺) over the synthesized V₂O₅/g-C₃N₄ by MCM-41 and F-127 templates under the visible light. V₂O₅ nanoparticles (NPs) were incorporated to g-C₃N₄ with the percentages of 0.3, 0.6, 0.9 and 1.2 wt%. The synthesized heterojunctions were verified to have large surface areas of 188–206 m² g⁻¹. It has been shown by TEM analysis that the constructed nanocomposites consist of uniformly dispersed V₂O₅ NPs over the g-C₃N₄ surface. The estimated bandgap energy is reduced from 2.7 eV for the pure g-C₃N₄ to 2.31 eV for the 1.2% V₂O₅/g-C₃N₄. The reduction of Hg²⁺ ions over the nanocomposite containing 0.9 wt% V₂O₅ under visible light was accomplished with the greater rate (480.23 µmol g⁻¹ h⁻¹), especially when compared to those over pure V₂O₅ NPs (110.00 µmol g⁻¹ h⁻¹) or pure g-C₃N₄ (85.22 µmol g⁻¹ h⁻¹). The optimized heterojunction achieved the entire reduction of Hg²⁺ after illumination by visible light whereas, only 23 and 16% of Hg²⁺ were reduced when pure V₂O₅ NPs and pure g-C₃N₄, respectively, were applied. The promoted achievement of the progressed heterojunction is ascribed to numerous factors like boosted surface area, confined bandgap, uniform dispersion of V₂O₅, and photocharge recombination suppression. The outstanding photocatalytic applicability of the V₂O₅/g-C₃N₄ heterojunctions was reached after reusing five times to reduce Hg²⁺ under visible light, implying the appreciable stability. This work highlights the practical use of modified g-C₃N₄-based photocatalysts for green remediation of water systems.

Graphic Abstract

中文翻译：

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在可见光下促进汞 (II) 离子还原的介孔 V2O5/g-C3N4 纳米复合材料

摘要

本研究成功地尝试在可见光下通过 MCM-41 和 F-127 模板促进合成的 V ₂ O ₅ /gC ₃ N _{4 上}的汞离子 (Hg ²⁺ )的光催化还原。V ₂ O ₅纳米颗粒(NP)以0.3、0.6、0.9和1.2wt％的百分比结合到gC ₃ N _{4 中}。合成的异质结被证实具有188-206 m ²  g ^{-1 的}大表面积。TEM 分析表明，所构建的纳米复合材料由均匀分散的 V ₂ O _{5 组成}gC ₃ N ₄表面上的纳米颗粒。估计的带隙能量从纯 gC ₃ N _{4 的}2.7 eV 降低到 1.2% V ₂ O ₅ /gC ₃ N _{4 的}2.31 eV 。在可见光下，含有 0.9 wt% V ₂ O ₅的纳米复合材料上 Hg ²⁺离子的还原速率更高（480.23 µmol g ^-1  h ^-1），尤其是与纯 V ₂ O ₅ NPs 相比时(110.00 µmol g ^-1  h ^-1 ) 或纯 gC ₃N ₄ (85.22 μmol g ^-1  h ^-1 )。优化的异质结在可见光照射后实现了 Hg ²⁺的完全减少，而当分别使用纯 V ₂ O ₅ NPs 和纯 gC ₃ N ₄时，Hg ²⁺仅减少了23% 和 16% 。进步异质结的促进成就归因于多种因素，例如增大的表面积、受限带隙、V ₂ O _{5 的}均匀分散和光电荷复合抑制。V ₂ O ₅ /gC优异的光催化适用性在可见光下重复使用五次以减少Hg ²⁺后达到₃ N ₄异质结，这意味着可观的稳定性。这项工作突出了改性 gC ₃ N ₄基光催化剂在水系统绿色修复中的实际应用。

图形摘要