Lanthanum (La) (oxy)hydroxides are promising adsorbents for efficient aqueous phosphate (P) removal. The incorporation of cationic hydrogel with La hydroxides represents an effective strategy to improve the dispersion of La–O active sites thereby favoring P adsorption. In this study, a hydrogen (H) bond-capping via organic–inorganic copolymerization strategy was developed for enhancing the dispersion of La–O active sites. This approach significantly enhanced the adsorption capacity of La hydroxide oligomer (LHO) copolymerized cationic hydrogel (LaCCH) to 308.2 mg_P g_La⁻¹. Fixed-bed experiments demonstrated that LaCCH effectively treated over 1098 bed volumes (BV) of synthetic wastewater (1.0 mg_P L⁻¹) containing co-existing ions. Combined analyses using FTIR, Raman, and XPS confirmed that the inner-sphere complexation and formation of LaPO₄·0.5H₂O were crucial to P adsorption. The results of MD simulation implied the weaker intermolecular H bonding between [La(OH)₃] in LaCCH results in a more favorable interaction between [La(OH)₃] and the hydrogel carbon chain. In summary, copolymerization significantly improved the dispersion of La–O active sites, which enhanced P adsorption and demonstrated a strong correlation between the fractal dimension of dispersion and adsorption capacity.

中文翻译：

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通过氢键加帽有机-无机共聚策略调整 La-O 吸附位点分散，以增强磷酸盐去除


镧 （La） （氧）氢氧化物是有效去除磷酸盐水 （P） 的有前途的吸附剂。阳离子水凝胶与 La 氢氧化物的掺入代表了改善 La-O 活性位点分散从而有利于 P 吸附的有效策略。在这项研究中，开发了一种通过有机-无机共聚策略实现氢 （H） 键封端，以增强 La-O 活性位点的分散。这种方法显著提高了氢氧化物低聚物 （LHO） 共聚阳离子水凝胶 （LaCCH） 的吸附能力至 308.2 mg_P g ^La-1。固定床实验表明，LaCCH 有效处理了超过 1098 床体积 （BV） 的含有共存离子的合成废水 （1.0 mg_P ^L-1）。使用 FTIR、Raman 和 XPS 进行联合分析，证实 LaPO₄·0.5H₂O 的球内络合和形成对 P 吸附至关重要。MD 模拟结果表明，LaCCH 中 [La（OH）₃] 之间的分子间 H 键较弱，导致 [La（OH）₃] 和水凝胶碳链之间的相互作用更有利。综上所述，共聚显著改善了 La-O 活性位点的分散性，从而增强了 P 吸附，并证明了分散体的分形维数与吸附能力之间存在很强的相关性。