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ú³100 nm Ì Si3N4 uÅª¯çêÄ¢éBN_KkãNÉCI»´qüÓÌÇ\¢CÁÉÅßÚÌ´qzû[ÌªèÌÉÍCSiC uðp¢éBî Xâ£ªÏ»·éNX^[\Ê\¢âaür[CÉÚ±µÄ¢éÌæÛÍ´^óºÉ\¢ÈÇðð·é±ÆªÂ\ÉÈèC±êÜÅmé±Æªïµ©ÁéBÌæÜÆÞÍí³ÌwEÅ½³êÄ¢éBî½½¬ªnÌNX^[ântÌÇ\¢ðmé±ÆªÅ

X üÍÌæÛCÌæÜCtÌwiÌæÝjðoÄCÌæ«éæ¤ÉÈéÆúÒ³êéBÞÌtHg_CI[hoíÅo³êéBXAS XyN»±ÅÜ¸C30ÂöxÌ¬³È Kr_Xe ¬NX^[

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ÉC¬NX^[Ì¤©ç¬ntÌ¤Éd_ðVtgµÄCntÌ§ß@Éæé XAS ªèÉæèg

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éB±êÜÅÍC§ß@ÌãpÆµÄCuõûÊ5) CtÌWFbgâtHðp¢½SdqûÊ6) CCIûÊ6,7) CI[WFdqûÊ8) ÈÇCî X üzûÊÉäáµÄN±éàkãNÌñßöÌûÊ@ªp¢çêÄ«½BÜ½d X üÌdq}Ußöðp¢éáàé9)B±êçÌXyNgÅÍuõÌ©ÈzûâdqÌñe«UÈÇCé¢Í½iKÌßöªÜÜêé½ßCoNÌtÌÌõzûXyNgÉÍêv¹¸Cc_ÌÛÉÓ·éKvªéBäXÍtÌwÌú³ð20

nm_2000 nm ÌÍÍÅ²®Â\ÈtÌZðJ­µÄC§Fig. 1.

ß@ÉæétÌÌ XAS ªèðÂ\Éµ½10)B{eÅÍÁÉ§ß@ XAS ªèÌ½ßÌtÌZÌJ­ÆC^m[ntÌa«ÝìpÌÇ\¢ð

C_K zû[ XAS ©ç²×½¤ÉÂ¢ÄÐî·éBÜ½C±ÌtÌZÉdÉðõ¦½dC»wZðJ­µÄC°_SntÌdC»w½É¨¯éCntÌSCSchematic of the liquid cell for XAS in transmission mode.
Region I is connected to beamline under vacuum. Regions IIand IV are at atmospheric pressure of helium gas. The thinliquid layer (region III) is sandwiched between two Si3N4membranes. Soft X­rays, which pass through region II andthe liquid layer (region III), are detected by a photodiode inregion IV. The details of the liquid cell are described in thetext.

106  úËõ March 2014 Vol.27 No.2(C) 2014 The Japanese Society for Synchrotron Radiation ResearchFig. 2úËõj[X ¡ æ18ñú{úËõwï§ãÜóÜ¤ñFig. 3(a) C K­edge XAS spectra of methanol­water binary solu­
tions at dierent concentrations at 25
C. The mixing ratio ofmethanol in the solution decreases with molar fraction stepsof 0.1 along indicated arrows. (b) Fraction of the pure liquidmethanol contribution in the second peak in the C K­edge
XAS spectra as a function of the methanol molar fraction(X) in the solution (CH3OH)X(H2O)1_X, which is obtainedby tting from a superposition of pure liquid methanol (X1.0) and the dilute methanol solution (X0.05). Threecharacteristic regions are found with the borders of X0.7and X0.3.

O K­edge XAS spectra of liquid water at dierent thicknessof the liquid layer, which is estimated from the edge­jump inthe spectra. The inset shows the schematic of the thin liquidlayer, in which the thickness of the liquid layer is controllable
between 20 and 2000 nm by adjusting the helium pressure.

³êÄ¢é½ßCåC³ðºÅéBÜ½t|vÉæètÌ¿ðCð··é±ÆªÂ\ÅéB§ß@ÅÍC¿ÉÜÜêéSÄÌ³fÌÊð©ÏàÁÄCî
X üÌzûÊªÅKÉÈéæ¤É¿ú³ð²®·éKvªéB±ÌtÌZÅÍCÌæÜÆÌæÞð½·w

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é±ÆÅCtÌwÌú³ð20 nm_2000 nm ÌÍÍÅ²®
Â\Åé10)BtÌwð\¬·é Si3N4 uÌå«³Í 2~2 mm2 ÅéBêûC^óÌæÛÆwEÌæÜÌÔÌÍ0.2~0.2 mm2 Æ¬³¢B±êÍ³Í·ÅªjêÈ¢æ¤É·é±ÆÈOÉàÚIª3.

^m[ntÌaªqÍ 2 ÂÌéBÌæÝÌ

«ÝìpÌÇ\¢fhi[TCgÆ»Ì½Î¤É¼ð¿ú³ÍêlÅÍÈ¢ÌÅCî X üð§ß·éªÌ·é 2 ÂÌ¿úÝðêèÉ·é½ßÉCr[TCYð¬³­·élbg[NÍ 3 ³ÉÈéBêûC^m[Í 1½ßÅ

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fhi[TCgµ©È­C»Ìãíèaf«Ì`éB»Ì½ßtÌÅÍ 6_8 ÂÌ^m[ªqCÌð¬·êÎC»ÌCÌÌ XAS XyNgð¯ÉîªªèÅ«éB±êÉæÁÄCüËõÌGlM[Z³¾¯©çÈé 1 ³Ì½ó\¢© 2 ³ÌÂ\¢ªÅ«éÆÅÈ­C¯¶¿ÅCÌÆtÌÌXyNgVtgð¸§l¦çêÄ¢é12) B»ÌÊC^m[Éè·é±ÆªÂ\ÅntÅÍflbg[NÌ³«ª¡GÉÈéÆ\z³êéBéB

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Ì O_K zû[«qñÜ©çC3 ³IÈ¬NX^[ð`¬·é±Ì XAS XyNgð¦·BtÌwÌüèÌwE³ð

Æª¦´³êÄ¢éª13) C»ÌÇ\¢ÌÚ×ÍÜ¾æ

²®·é±ÆÅCÙÈéú³ÌÌ XAS XyNgªª­ª©ÁÄ¢È¢B»±ÅlXÈ¬ä¦Ì^m[è³êÄ¢é±Æªª©éBXAS XyNgÌGbWWntÌ C_K zû[ XAS ªèðs¢C^m[vÌ³ÆtÌwÌú³Íäá·éÌÅCGbWWÌavÌ³ÆtÌÌzûW©çCtÌwÌú³ðßnt«ÝìpÌÇ\¢ÌÏ»ð²×½BFig. 3(a)ÉÙÈéZxÌ^m[ntiCH3OH)XÄ¢éBÜ½tÌwª20 nm Ìú³Ì XAS ªèªÂ\Å(H2O)1_X Ì C_K zû[ XAS XyNgð¦·B2 ÂÌèCo NÌtÌ¾ ¯ÅÈ­C ÅtEÊð ­²µ½

zû[Os[NªÏª³êÄ¢éªCÅÌ288 eV tß

XAS ªèªs¦é±Æà¦µÄ¢éBÌs[NÍC_î¬ªðÜÞªqSÌÉLªé^m[ ªq Ì 8a
ÞO ¹©ç Èé óÊ ÖÌ ãNÉ A®³ êúËõ March 2014 Vol.27 No.2  107éBêûC2 ÔÚÌ290 eV tßÌs[NÍCåÉ`î¬ªðÜÞ 9a
ÞO¹©çÈéóÊÖÌãNÉA®³êéB»Ì½ßC±Ìs[NÍ`îüèÌaìpÉq´Å«ÝéÆl¦çêéBÀÛCÅÌs[NÍÜèZxË¶«ð¦³È¢ªC2 ÔÚÌs[NÍÌª¦éÙÇGlM[¤ÉVtg·éBÜ½±Ìs[NÍ290 eV tßÉzû_ð¿C`îüèª^m[ÉÍÜê½êÆCÉÍÜê½êÉª¯é±ÆªÅ«éB»±Å±Ìs[NðÜÞ288.5_290.5 eV ÌGlM[ÍÍÅC`îÆ^m[ÆÌÝìpð½f·étÌ^m[iX1.0jÆC`îÆÝìpð½f·éóÈÆÌntiX0.05jÌ XAS XyNgÌdËí¹©çCtBbeBOðsÁ½B
Fig. 3(b)É`îüèÌÝìpÉ¨¯éC^m[ªqÌñ^ÌZxË¶«ð¦·B­xÏ»ÉÍå«­ 3ÂÌÌæªéBÜ¸^m[ªxzIÈÌæÛiX0.7jÅÍCÌª¦ÄàCXyNgÍÙÆñÇÏ»¹¸C`îüèÌa«ÝìpÍtÌ^m[ÌàÌÆÙÚ¯¶ÅðXÉâ·ÆC^m[éBÌäª 2F1Æ½èÅ]ÚI®ð¦µÄCÌæÜi0.7X0.3jÉüéB»ÌÈ¢B^m[Ì 1 ³Â©ÌÆÍÜèÏ»µé¢Í 2 ³\¢ÌÉôªqªgÝÜêC3 ³«ðÑÑ½V½È\¢ªSÉÈèC»Ì\¢ÅÌaFig. 4Schematics of three electrodes included in the liquid layer(region III). The working electrode (WE) is Au­deposited
on a Si3N4 membrane. The counter electrode (CE) is a Ptmesh. The reference electrode (RE) is Ag/AgCl immersed ina saturated KCl solution.

½µ½ Ag/AgCl dÉðp¢½BQÆÉðetÅ¢¤±ÆÉæèCOa KCl ntð¿ntÆª£µ½BdÉÌdÊÏ»Í|eVX^bgðp¢ÄsÁ½B®¬µ½dC»wZðp¢ÄC°_SntÌ Fe_L

zû[ XAS ªèðsÁ½11)BFig. 5 É°_Snti0.5

Ýìpà¿¢Ä¢ª¦Ä^m[ÆÌM, pH2.2jÌCÙÈédÊÉ¨¯é Fe_L zû[ XASäª 1F2 ÆÈéÓèÅCÌæÝi0.3XjÉÈéBÌæXyNgð¦·B»ê¼êÌXyNgÍêèdÊÅªéÆl¦çêéB³çÉÌ 3 ³lbg[NªèµÄCªèãÉÌdÊÉÚsµÄCXyNgªè·ªqªßÃ­ 3é Ìð J èÔ µ½ BX yN g ª èÍ 0.05 V ² ÆÉ s

³\¢ª`¬³êÄ­éB±Ìæ¤ÈÇ\¢Ï»Íª¢CêÂÌªèÉ10ªöxv·é½ßCdÊÌ|ø¬xq®ÍwV~[VÉæÁÄàÄ»³êÄ¢éBÈ

Í0.08 mV/s ÆÈéBFig. 5(a)É¦·æ¤ÉCdÉdÊð¨C¨«IÉÍÌæÜÆÌæÝÌ«EüÓÌª¦ÅSã°éÆCFe(II) ©ç Fe(III) ÖÌ_»ªis·éBêxªÅåÉÈé±ÆªmçêÄ¨èCî X üzûªõ©

û C Fig. 5( b)É¦ · æ¤ É Cd Éd Ê ðº ° éÆ CFeÝÅÍª¦éÆÆàÉCxzIÉÈÁÄ¢«C`îÌüèÉçª©Á½ 3 ³«ðÑÑ½V½È^m[ÆÌl(III) ©ç Fe(II) ÖÌÒ³ªN±éBÒ³ßöÅÍ XAS
XyNgªCdÉdÊÉÎµÄü`ÉÏ»·éÌÉÎµbg[N\¢ÆÌÖAà¦´³êéBntÈOÌlXÈntÉÂ¢ÄàCÄC_»ßöÅÍñü`ÉÏ»·é±Æªª©Á½B»±

C_K, N_K, O_K zû[ XAS ªèÉæÁÄÇ\¢Ì¤ÅC»ê¼êÌ XAS XyNgð Fe(II) Æ Fe(III) ÌWðÏÝdËÄ¢éÆ±ëÅXyNgÅtBbeBO·é±ÆÉæèCntÌ»ÝC^m[éB³çÉ¡ãCõ»w½ÈÇÖÌpàvæµÄ¢éBFe(II) Æ Fe(III) Ì¶Ýä¦ðß½B4.

CIÌ¶Ýä¦ð¦·BdÊã¸Éæé Fe(II) Ì_»

Fig. 5(c)ÉÙÈédÉdÊÉ¨¯éCntÌ Fe(II)°_SntÌdC»w½Ì XAS ªè11)ntÌdC»w½ðð·éãÅCdCñdwðÜÞdð¿ntÌÇ\¢ð²×é±ÆªdvÅéB»±ßöÉæèCFe(II) Ìª¸­·éBêûCdÊ~ºÉæé Fe(III) ÌÒ³ßöÉæèCFe(II) Ìª¦ÅäXÍ§ß@ XAS ªèÌ½ßÌtÌZÉdÉðõ¦éBÒ³ßöÍ 1 ÂÌßöi0.29 VjÅ

é±ÆÉæèCdC»w½Ìdð¿ntÌ XAS ªè_»ßöÉÍ 2 ÂÌßöi0.34 V, 0.72 Vjª

ðÂ\Éµ½BFig. 1 Å¦µ½tÌZÉìpÉCÎÉCª©Á½BéÌÉÎµÄC
é±ÆªQÆÉðÝuµ½BFig. 4 ÉÝuµ½dÉÌÍ®}ð¦ÈãÌ_»Ò³ßöð²×é½ßÉCÙÈédÊ|ø¬·BtÌwiÝjð\¬·é 1 Ì Si3N4 uðC

xi5 mV/s, 20 mV/sjÅTCNbN{^g[µ½ Si3N4 uÉµÄìpÉÆµ½BÎÉiCVjªèðsÁ½BÒ³ßöÉÂ¢ÄÍC|ø¬xðÏðp¢½BQÆÉÉÍOa KCl ntÅ¦Äàs[NlÍÙÆñÇ XAS ÌÊÆÏíçÈ©ÁàðöÉÍàbV108  úËõ March 2014 Vol.27 No.2úËõj[X ¡ æ18ñú{úËõwï§ãÜóÜ¤ñÓ«{eÅq×½¤ðxµÄ¸¢½ªqÈw¤Ì¬M³öÉ[­´ÓvµÜ·BNX^[¤ÅÍx©RåwÌ Eckart R äuhl ³öCdC»w¤ÅÍ}bN}X^[åwÌ Adam P. Hitchcock ³öÆÌ¤¯¤ªdvÅµ½BZpJ­ÖWÅÍCO¬O[vÌäFLmi»w¤jCUVSOR {ÝZpEõÌxÄvÌxª©¹Ü¹ñÅµ½BÜ½CUVSOR {ÝX^btÌxÅM«éªèªÂ\ÉÈÁÄ¢Ü·BÅßÌ¤ÅÍ¬O[vÌòElmC@¶Ì]
¢É¯çêÄ¢Ü·B±Ìêð¨ØèµÄ[­´ÓvµÜ·BQl¶£1)2)3)Fig. 5Fe L­edge XAS spectra of Fe ions in a 0.5 M aqueous ironsulfate at dierent potentials: (a) increasing from 0.0 to 0.9
V and (b) decreasing from 0.9 to |0.4 V. The applied
potential in the XAS spectra are changed in the direction ofarrows. (c) Fraction of Fe(II) ions as a function of potential
versus Ag/AgCl with saturated KCl solutions, which is ob­
tained by tting the XAS spectra at dierent potentials to asuperposition of the reference spectra of Fe(II) and Fe(III)ions. The arrows indicate the scanning direction of appliedpotential.

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