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Author Huang, S.; Griffin, E.; Cai, J.; Xin, B.; Tong, J.; Fu, Y.; Kravets, V.; Peeters, F.M.; Lozada-Hidalgo, M. url  doi
openurl 
  Title Gate-controlled suppression of light-driven proton transport through graphene electrodes Type A1 Journal article
  Year (down) 2023 Publication Nature communications Abbreviated Journal  
  Volume 14 Issue 1 Pages 6932-6937  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Recent experiments demonstrated that proton transport through graphene electrodes can be accelerated by over an order of magnitude with low intensity illumination. Here we show that this photo-effect can be suppressed for a tuneable fraction of the infra-red spectrum by applying a voltage bias. Using photocurrent measurements and Raman spectroscopy, we show that such fraction can be selected by tuning the Fermi energy of electrons in graphene with a bias, a phenomenon controlled by Pauli blocking of photo-excited electrons. These findings demonstrate a dependence between graphene's electronic and proton transport properties and provide fundamental insights into molecularly thin electrode-electrolyte interfaces and their interaction with light. Recent experiments have shown that proton transport through graphene electrodes can be promoted by light, but the understanding of this phenomenon remains unclear. Here, the authors report the electrical tunability of this photo-effect, showing a connection between graphene electronic and proton transport properties.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001094448600003 Publication Date 2023-10-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:201185 Serial 9041  
Permanent link to this record
 

 
Author Wahab, O.J.; Daviddi, E.; Xin, B.; Sun, P.Z.; Griffin, E.; Colburn, A.W.; Barry, D.; Yagmurcukardes, M.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M.; Unwin, P.R. url  doi
openurl 
  Title Proton transport through nanoscale corrugations in two-dimensional crystals Type A1 Journal article
  Year (down) 2023 Publication Nature Abbreviated Journal  
  Volume 620 Issue 7975 Pages 1-17  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Defect-free graphene is impermeable to all atoms(1-5) and ions(6,7) under ambient conditions. Experiments that can resolve gas flows of a few atoms per hour through micrometre-sized membranes found that monocrystalline graphene is completely impermeable to helium, the smallest atom(2,5). Such membranes were also shown to be impermeable to all ions, including the smallest one, lithium(6,7). By contrast, graphene was reported to be highly permeable to protons, nuclei of hydrogen atoms(8,9). There is no consensus, however, either on the mechanism behind the unexpectedly high proton permeability(10-14) or even on whether it requires defects in graphene's crystal lattice(6,8,15-17). Here, using high-resolution scanning electrochemical cell microscopy, we show that, although proton permeation through mechanically exfoliated monolayers of graphene and hexagonal boron nitride cannot be attributed to any structural defects, nanoscale non-flatness of two-dimensional membranes greatly facilitates proton transport. The spatial distribution of proton currents visualized by scanning electrochemical cell microscopy reveals marked inhomogeneities that are strongly correlated with nanoscale wrinkles and other features where strain is accumulated. Our results highlight nanoscale morphology as an important parameter enabling proton transport through two-dimensional crystals, mostly considered and modelled as flat, and indicate that strain and curvature can be used as additional degrees of freedom to control the proton permeability of two-dimensional materials. A study using high-resolution scanning electrochemical cell microscopy attributes proton permeation through defect-free graphene and hexagonal boron nitride to transport across areas of the structure that are under strain.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001153630400007 Publication Date 2023-08-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836; 1476-4687 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:203827 Serial 9078  
Permanent link to this record
 

 
Author Cai, J.; Griffin, E.; Guarochico-Moreira, V.; Barry, D.; Xin, B.; Huang, S.; Geim, A.K.; Peeters, F.M.; Lozada-Hidalgo, M. url  doi
openurl 
  Title Photoaccelerated water dissociation across one-atom-thick electrodes Type A1 Journal article
  Year (down) 2022 Publication Nano letters Abbreviated Journal Nano Lett  
  Volume 22 Issue 23 Pages 9566-9570  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Recent experiments demonstrated that interfacial water dissociation (H2O ⇆ H+ + OH-) could be accelerated exponentially by an electric field applied to graphene electrodes, a phenomenon related to the Wien effect. Here we report an order-of-magnitude acceleration of the interfacial water dissociation reaction under visible-light illumination. This process is accompanied by spatial separation of protons and hydroxide ions across one-atom-thick graphene and enhanced by strong interfacial electric fields. The found photoeffect is attributed to the combination of graphene's perfect selectivity with respect to protons, which prevents proton-hydroxide recombination, and to proton transport acceleration by the Wien effect, which occurs in synchrony with the water dissociation reaction. Our findings provide fundamental insights into ion dynamics near atomically thin proton-selective interfaces and suggest that strong interfacial fields can enhance and tune very fast ionic processes, which is of relevance for applications in photocatalysis and designing reconfigurable materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000892112200001 Publication Date 2022-11-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 10.8 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 10.8  
  Call Number UA @ admin @ c:irua:192759 Serial 7330  
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Author Cai, J.; Griffin, E.; Guarochico-Moreira, V.H.; Barry, D.; Xin, B.; Yagmurcukardes, M.; Zhang, S.; Geim, A.K.; Peeters, F.M.; Lozada-Hidalgo, M. url  doi
openurl 
  Title Wien effect in interfacial water dissociation through proton-permeable graphene electrodes Type A1 Journal article
  Year (down) 2022 Publication Nature communications Abbreviated Journal Nat Commun  
  Volume 13 Issue 1 Pages 5776-5777  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Strong electric fields can accelerate molecular dissociation reactions. The phenomenon known as the Wien effect was previously observed using high-voltage electrolysis cells that produced fields of about 10(7) V m(-1), sufficient to accelerate the dissociation of weakly bound molecules (e.g., organics and weak electrolytes). The observation of the Wien effect for the common case of water dissociation (H2O reversible arrow H+ + OH-) has remained elusive. Here we study the dissociation of interfacial water adjacent to proton-permeable graphene electrodes and observe strong acceleration of the reaction in fields reaching above 10(8) V m(-1). The use of graphene electrodes allows measuring the proton currents arising exclusively from the dissociation of interfacial water, while the electric field driving the reaction is monitored through the carrier density induced in graphene by the same field. The observed exponential increase in proton currents is in quantitative agreement with Onsager's theory. Our results also demonstrate that graphene electrodes can be valuable for the investigation of various interfacial phenomena involving proton transport.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000862552600012 Publication Date 2022-10-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 16.6 Times cited 3 Open Access OpenAccess  
  Notes Approved Most recent IF: 16.6  
  Call Number UA @ admin @ c:irua:191575 Serial 7228  
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