Overcoming humidity-induced swelling of graphene oxide-based hydrogen membranes using charge-compensating nanodiamonds
Overcoming humidity-induced swelling of graphene oxide-based hydrogen membranes using charge-compensating nanodiamonds
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DOI：
10.1038/s41560-021-00946-y
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发表时间：
2021-12-01
期刊：
影响因子：
56.7
通讯作者：
Sivaniah, Easan
中科院分区：
文献类型：
--
作者：
Huang, Guoji;Ghalei, Behnam;Sivaniah, Easan
氧化石墨烯(GO)可以形成超渗透和超选择性的膜，在包括氢气净化在内的各种气体分离应用中具有广阔的应用前景。然而，在潮湿的条件下，GO膜失去了诱人的分离性能。在这里，我们展示了将带正电的纳米钻石(ND(+)S)掺入GO纳米层酸盐中，可以获得耐湿但高性能的膜。虽然原生GO膜在一次运行中就会失效，但GO/ND+复合材料在侵入性湿度测试下经过几次循环后，对二氧化碳的H-2选择性保持了大约90%。带负电荷的NdGO的加入没有带来这种稳定性，这表明电荷补偿是赋予湿阻的主要机制，而Nd2+S中和了负电荷的GO片。我们观察到当带正电的多面体低聚倍半硅氧烷取代ND+时，也有类似的稳定效果，但效果较差。展示的材料平台提供了一种解决方案，可以将H-2气体从化石燃料来源或水分离产生的通常潮湿的混合物中分离出来。氧化石墨烯的渗透特性使其成为一种有希望的氢气净化材料，但湿度会导致有害的膨胀。在这里，作者通过将带正电的纳米钻石加入到石墨烯氧化物薄膜中来解决这个问题，稳定了结构，并将性能降级降至最低。
Graphene oxide (GO) can form ultrapermeable and ultraselective membranes that are promising for various gas separation applications, including hydrogen purification. However, GO films lose their attractive separation properties in humid conditions. Here we show that incorporating positively charged nanodiamonds (ND(+)s) into GO nanolaminates leads to humidity-resistant, yet high-performing, membranes. While native GO membranes fail at a single run, the GO/ND+ composite retains up to roughly 90% of GO's H-2 selectivity against CO2 after several cycles under an aggressive humidity test. The addition of negatively charged ND to GO brought no such stabilization, suggesting that charge compensation acts as the main mechanism conferring humidity resistance, where ND(+)s neutralize the negative charge GO sheets. We observed a similar but inferior stabilization effect when positively charged polyhedral oligomeric silsesquioxane replaces ND+. The demonstrated material platform offers a solution for separating H-2 gas from its usually humid mixtures generated from fossil fuel sources or water splitting.Graphene oxide's permeation properties make it a promising material for purification of hydrogen, but humidity can cause deleterious swelling. Here the authors remedy this by incorporating positively charged nanodiamonds into graphene oxide membranes, stabilizing the structure and minimizing performance degradation.