Liang Caihong, Yen Zhihao, Salim Teddy, Lam Yeng Ming
School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
Facility for Analysis, Characterization, Testing and Simulation (FACTS), Nanyang Technological University, Singapore, 639798, Singapore.
Phys Chem Chem Phys. 2023 Nov 29;25(46):31874-31883. doi: 10.1039/d3cp03263a.
Dialysis is an artificial process to remove excess urea toxins from the body through adsorption or conversion. Urea adsorption by emergent 2D materials such as MXenes is one probable approach. Based on density functional theory (DFT) studies, the surface of TiCT (T = -O- and -OH) MXenes is not optimum for urea adsorption. Therefore, functionalization with 3d metal dopants (Cu, Co, and Ni) is proposed to improve their urea adsorption ability. DFT calculations indicate that oxygen-terminated TiCO has a much better urea adsorption ability when doped with Cu, Co, and Ni, with adsorption energy () values of -2.11 eV, -1.90 eV and -1.72 eV, respectively. These adsorption energies are much more favourable than that of the undoped one ( = -0.52 eV). To verify the calculation results, MILD TiCT, or MXenes synthesized the safer and easier minimally intensive layer delamination (MILD) method, were utilized to simulate TiCO since they have -O- termination as the dominant species. Experimentally, the adsorption studies found that low concentration of Cu, Co, and Ni on MILD TiCT showed a urea removal efficiency of 21.9%, 6.0% and 0.2%, respectively, much better than 0% removal efficiency of unfunctionalized TiCT. Therefore, both DFT calculations and experiments showed that various metal functionalized MXenes have a similar trend for urea adsorption, highlighting the feasibility of using the computational approach to predict urea adsorption and further opening a new promising direction for the urea adsorption. Finally, this study is also the first to examine synergistic effects of metal dopants and surface terminations on MXenes for urea adsorption.
透析是一种通过吸附或转化从体内去除多余尿素毒素的人工过程。利用二维材料（如MXenes）进行尿素吸附是一种可能的方法。基于密度泛函理论（DFT）研究，TiCT（T = -O- 和 -OH）MXenes的表面对于尿素吸附并非最佳。因此，有人提出用3d金属掺杂剂（铜、钴和镍）进行功能化处理，以提高其尿素吸附能力。DFT计算表明，当用铜、钴和镍掺杂时，氧端基的TiCO具有更好的尿素吸附能力，吸附能（）值分别为-2.11 eV、-1.90 eV和-1.72 eV。这些吸附能比未掺杂的TiCO（ = -0.52 eV）更有利。为了验证计算结果，采用更安全、更简便的微强度层状剥离（MILD）法合成的MILD TiCT来模拟TiCO，因为它们以-O-端基为主。实验发现，在MILD TiCT上低浓度的铜、钴和镍的尿素去除效率分别为21.9%、6.0%和0.2%，远高于未功能化TiCT的0%去除效率。因此，DFT计算和实验均表明，各种金属功能化的MXenes在尿素吸附方面具有相似的趋势，突出了使用计算方法预测尿素吸附的可行性，并为尿素吸附开辟了一个新的有前景的方向。最后，本研究也是首次考察金属掺杂剂和表面端基对MXenes尿素吸附的协同效应。
