Aqueous proton transfer across single-layer graphene.
Aqueous proton transfer across single-layer graphene.
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DOI：
10.1038/ncomms7539
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发表时间：
2015-03-17
影响因子：
16.6
通讯作者：
Geiger, Franz M.
中科院分区：
文献类型：
--
作者：
Achtyl, Jennifer L.;Unocic, Raymond R.;Xu, Lijun;Cai, Yu;Raju, Muralikrishna;Zhang, Weiwei;Sacci, Robert L.;Vlassiouk, Ivan V.;Fulvio, Pasquale F.;Ganesh, Panchapakesan;Wesolowski, David J.;Dai, Sheng;van Duin, Adri C. T.;Neurock, Matthew;Geiger, Franz M.
质子在单层石墨烯上的转移具有较大的计算能垒，因此被认为在室温下是不利的，除非引入纳米级空穴或掺杂剂，或者施加潜在的偏置。在这里，我们将熔融二氧化硅支撑的单层石墨烯置于高pH值和低pH值的循环中，并表明质子从水相通过石墨烯可逆地转移到另一侧，在那里它们与二氧化硅羟基发生酸碱化学反应。在排除了通过宏观针孔的扩散后，发现质子通过罕见的、自然发生的原子缺陷转移。计算机模拟显示，水溶液中质子通过羟基端端原子缺陷转移的低能垒为0.61-0.75 eV，参与grotthuss型中继，而类pyryl醚端端则关闭质子交换。不利于氦和氢转移的能量障碍表明该过程对水质子是选择性的。质子在石墨烯上的转移与较大的计算能垒有关，通常被认为是不利的。在这里，作者观察到水溶液中的质子通过石墨烯进行pH循环，表明这是由于通过罕见的、自然发生的原子缺陷进行的转移。
Proton transfer across single-layer graphene proceeds with large computed energy barriers and is therefore thought to be unfavourable at room temperature unless nanoscale holes or dopants are introduced, or a potential bias is applied. Here we subject single-layer graphene supported on fused silica to cycles of high and low pH, and show that protons transfer reversibly from the aqueous phase through the graphene to the other side where they undergo acid–base chemistry with the silica hydroxyl groups. After ruling out diffusion through macroscopic pinholes, the protons are found to transfer through rare, naturally occurring atomic defects. Computer simulations reveal low energy barriers of 0.61–0.75 eV for aqueous proton transfer across hydroxyl-terminated atomic defects that participate in a Grotthuss-type relay, while pyrylium-like ether terminations shut down proton exchange. Unfavourable energy barriers to helium and hydrogen transfer indicate the process is selective for aqueous protons. Proton transfer across graphene is associated with large computed energy barriers and is thought to be generally unfavourable. Here, the authors observe aqueous proton transfer through graphene subjected to pH cycling, suggesting that it is due to transfer through rare, naturally occurring atomic defects.
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影响因子：
3.3
作者：
Eikerling, M;Kornyshev, AA;Walbran, S
通讯作者：
Walbran, S
影响因子：
5.7
作者：
Hauser, Andreas W.;Schwerdtfeger, Peter
通讯作者：
Schwerdtfeger, Peter
影响因子：
3.3
作者：
Achtyl, Jennifer L.;Vlassiouk, Ivan V.;Geiger, Franz M.
通讯作者：
Geiger, Franz M.
影响因子：
3.7
作者：
Hammouchi, M;El Boudouti, EH;Dobrzynski, L
通讯作者：
Dobrzynski, L
DOI：
10.1073/pnas.92.2.372
发表时间：
1995-01-17
影响因子：
11.1
作者：
ALEXIEV, U;MOLLAAGHABABA, R;HEYN, MP
通讯作者：
HEYN, MP