Layered double hydroxides are traditional positively charged inorganic materials generally considered as efficient and low-cost adsorbents for the removal of anionic organic molecules. In this study, we prepared a series of g-C₃N₄@NiCo LDH composites by loading 10–30 wt% of g-C₃N₄ onto the LDH through the electrostatic self-assembly method. The bare LDH and g-C₃N₄ loaded LDH composites were characterized by XRD, SEM-EDS, Zeta, DLS, and FTIR techniques. Results revealed that extra peak corresponds to g-C₃N₄ originating in the XRD patterns, distorted morphology of LDH, reduction in positive surface zeta potential, and enhancement in hydrodynamic size after loading of g-C₃N₄ affirmed the successful formation of the composite. The adsorption performance of as-modified LDH was evaluated by removing the most commonly used salicylic acid and methylene blue as anionic and cationic model pollutant, respectively, from aqueous solution. The adsorption mechanism for both the pollutants by as-synthesized samples follows Langmuir isotherm. The results demonstrated that the bare LDH exhibited maximum adsorption efficiency of 75.16 mg/g and only 3.66 mg/g for salicylic acid and methylene blue, respectively. With 30 wt% loading of g-C₃N₄, the adsorption capacity for methylene blue increased to 25.16 mg/g almost 6–7 times higher than that of bare LDH. On the other hand, the opposite effect on adsorptive removal of salicylic acid was observed with increase in the wt% loading of g-C₃N₄. With 30 wt% loading of g-C₃N₄, the adsorption capacity for salicylic acid decreased to 38.37 mg/g, almost half that of bare LDH. A possible mechanism has been proposed. The kinetics for adsorption of salicylic acid onto bare LDH obeys the second-order model aside from the methylene blue adsorption which follows first-order kinetics. On the other hand, the kinetics of adsorption for both the pollutants onto (10–30) CN- LDH composites follows second order kinetics.

层状双氢氧化物是传统的带正电荷的无机材料，通常被认为是去除阴离子有机分子的高效低成本吸附剂。在这项研究中，我们通过静电自组装方法将 10–30 wt% 的 gC ₃ N ₄负载到 LDH 上，制备了一系列 gC ₃ N ₄ @NiCo LDH 复合材料。负载LDH 和gC ₃ N _{4 的}LDH 复合材料通过XRD、SEM-EDS、Zeta、DLS 和FTIR 技术进行表征。结果显示额外的峰对应于 gC ₃ N ₄源自 XRD 图案、LDH 的变形形态、正表面 zeta 电位的降低以及加载 gC ₃ N ₄后流体动力学尺寸的增加证实了复合材料的成功形成。通过从水溶液中分别去除最常用的水杨酸和亚甲蓝作为阴离子和阳离子模型污染物来评估改性 LDH 的吸附性能。合成样品对两种污染物的吸附机制遵循朗缪尔等温线。结果表明，裸LDH对水杨酸和亚甲蓝的最大吸附效率分别为75.16 mg/g和3.66 mg/g。使用 30 wt% 的 gC ₃ N ₄，对亚甲基蓝的吸附容量增加到 25.16 mg/g，几乎是裸 LDH 的 6-7 倍。另一方面，随着gC ₃ N ₄的wt%负载量的增加，观察到对水杨酸的吸附去除的相反效果。随着gC ₃ N ₄负载量为30 wt% ，对水杨酸的吸附容量降低至38.37 mg/g，几乎是裸LDH 的一半。已经提出了一种可能的机制。除了遵循一级动力学的亚甲蓝吸附外，水杨酸在裸 LDH 上的吸附动力学遵循二级模型。另一方面，两种污染物在 (10-30) CN-LDH 复合材料上的吸附动力学遵循二级动力学。