• Bulletin of the Korean Chemical Society
• /
• 제31권12호
• /
• pp.3668-3674
• /
• 2010

Mesoporous SBA-15 was synthesized using tetraethylorthosilicate (TEOS) as the silica source and Pluronic (P123) as the structure-directing agent. The defective Si-OH groups present in SBA-15 were successively grafted with 3-chloropropyltrimethoxysilane (CPTMS) followed by tris-(2-aminoethyl) amine (TAEA) and/or tetraethylenepentamine (TEPA) for effective immobilization of silver nanoparticles. Grafting of TAEA and/or TEPA amine and immobilization of silver nanoparticles inside the channels of SBA-15 was verified by XRD, TEM, IR and BET techniques. The silver nanoparticles immobilized on TAEA and /or TEPA grafted SBA-15 was subjected for electrocatalytic reduction of hydrogen peroxide ($H_2O_2$). The TEPA stabilized silver nanoparticles show higher efficiency for reduction of $H_2O_2$ than that of TAEA, due to higher number of secondary amine groups present in TEPA. The amperometric analysis indicated that both the Ag/SBA-15/TAEA and Ag/SBA-15/TEPA modified electrodes required lower over-potential and hence possess high sensitivity towards the detection of $H_2O_2$. The reduction peak currents were linearly related to hydrogen peroxide concentration in the range between $3{\times}10^{-4}\;M$ and $2.5{\times}10^{-3}\;M$ with correlation coefficient of 0.997 and detection limit was $3{\times}10^{-4}\;M$.

• 대한화학회지
• /
• 제67권5호
• /
• pp.339-347
• /
• 2023

In this study, a nanocomposite of multi-walled carbon nanotubes@poly(p-phenylenediamine)-Prussian blue (MWCNTs@PpPD-PB) was synthesized and employed for the electrochemical detection of hydrogen peroxide (H₂O₂). A straightforward approach was utilized to prepare an electrochemical H₂O₂ sensor using a MWCNTs@PpPD-PB modified glassy carbon electrode, and its electrochemical behavior was investigated through techniques such as electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The modified electrode displayed a favorable electrocatalytic response towards the reduction of H₂O₂ in an acidic solution. The developed sensor exhibited linearity in the concentration range of 0.005 mM to 2.225 mM for H₂O₂, with high sensitivity (583.6 ㎂ mM^-1cm^-2) and a low detection limit (0.95 ㎛, S/N = 3) at an applied potential of +0.15 V (vs. Ag/AgCl). Additionally, the sensor demonstrated excellent selectivity, reproducibility, and stability. Moreover, successful detection of H₂O₂ was achieved in real samples.

• Bulletin of the Korean Chemical Society
• /
• 제35권2호
• /
• pp.431-435
• /
• 2014

Zinc peroxide nanoparticles ($ZnO_2$ NPs) were prepared by reacting zinc(II) isobutylcarbamate, as an organometallic precursor, with hydrogen peroxide ($H_2O_2$) at $60^{\circ}C$. Polyethylene glycol and polyvinylpyrrolidone were used as stabilizers, which suppressed aggregation of the $ZnO_2$ NPs. Conditions such as concentrations of $H_2O_2$ and the stabilizer were systemically controlled to determine their effect on the formation of nano-sized $ZnO_2$ NPs. The formation of stable $ZnO_2$ NPs was confirmed by UV-vis, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction. The TEM images revealed that polyvinylpyrrolidone-stabilized $ZnO_2$ NPs (diameter, 10-30 nm) were well dispersed in the organic solvent. Quite pure ZnO NPs were obtained from the peroxide powder by simple heat treatment of $ZnO_2$. The transition temperature of $170^{\circ}C$ was determined by differential scanning calorimetry.

• 한국대기환경학회지
• /
• 제17권1호
• /
• pp.31-38
• /
• 2001

Ambient ge-phase $H_2O$$_2$(Hydrogen Peroxide) concentrations were measured at four sites in downtown Seoul Korea. These measurements were mad during winter and summer, February 14~19 and 12~17, 1997. $H_2O$$_2$concentrations were quantified by fluorescence using enzyms. $H_2O$$_2$ concentrations in winter were below the limit of detection and was much higher concentrations in summer. The mean of all observations was 264 ppt and the range measured was 23ppt~1856ppt. The results from the correlation analysis showed that the concentration of gasous $H_2O$$_2$is dependent on the other air pollutants(O$_3$, NO$_2$) and meteorological parameter(solar radiation).

• Applied Biological Chemistry
• /
• 제33권2호
• /
• pp.129-132
• /
• 1990

저온에서 식물체중에 축적되는 과산화수소의 생리적 기능을 IAA수준의 조절과 관련하여 연구하였다. 과산화수소는 10mM농도에서 완두의 발근과 귀리 초엽의 신장을 억제하였으며 IAA의 호르몬 효과도 억제하였다. 이 억제효과는 catalase를 첨가하면 해제되었다. 유리의 IAA는 과산화수소와 반응하여 Salkowski시약에 민감하지 않은 어떤 복합체를 형성하여 과산화수소에 의하여 불활성화되는 것처럼 보였다. 그러므로 저온에서 식물체내에 축적된 과산화수소는 IAA를 불활성화하여 세포의 유용한 IAA수준을 하향조절하였을 것으로 여겨졌다.

• KSBB Journal
• /
• 제10권3호
• /
• pp.298-303
• /
• 1995

과산화수소는 유기물에 접촉시에 물과 산소로 급속하게 분해되어 탄수화물과 같은 고분자물질을 저 분자물질로 분해하는 특성을 지니고 였다. 이러한 특성이 inulin의 산 가수분해 반응에 미치는 영향을 초음파를 조사시키면서 연구하였다. 반응조건은 온도가 $50∼60^{\circ}C$ 엽산의 농도가 O.1~O.3%(w/w) 였고, 이 조건하에서 과산화수소 농도가 2.3% (w/v) 일 때 가수분해 효과가 최대로 나타났다. 과산화 수소의 첨가로 control 반응에 비해 9~43% 의 분 해속도 증가를 보였다. 과산화수소를 첨가했을 경우 와 첨가하지 않았을 경우에 활성화에너지는 각각 26kcal/mol과 25kcal/mol로 거의 통일하였다. 따라서 과산화수소에 의한 inulin 가수분해 속도의 상승 효과는 frequency factor의 증가로 해석되 었다.

• 생약학회지
• /
• 제27권4호
• /
• pp.328-335
• /
• 1996

Effects of hydrogen peroxide$(H_2O_2)$ on polyphenol oxidase (PPO) in Perillae Folium were investigated. The inactivation of this enzyme was dependent on $H_2O_2$ concentration. and the initial lag period was not shown. Preincubation of Perillae Folium PPO with $H_2O_2$ in the absence of a substrate resulted in rapid loss of enzymatic activity. The inactivation of PPO by $H_2O_2$ dependents temperature and pH. OH radical scavengers such as mannitol and sodium formate did not protect the enzyme against inactivation by $H_2O_2$. Substrate analogue such as phenylalanine protected the enzyme against inactivation by $H_2O_2$. and copper chelator such as sodium azide also protected the enzyme.

• 한국항공우주학회지
• /
• 제37권7호
• /
• pp.717-728
• /
• 2009

로켓추진기관에 있어 과산화수소는 단일추진제와 이종추진제의 산화제로 사용되어 왔다. 과산화수소는 추력기용으로 사용된 최초의 단일추진제였으나, 후에 보다 비추력이 높고 저장성이 좋은 하이드라진으로 대체되었고, 터보펌프 구동용으로는 여전히 사용되어지고 있다. 이종추진제의 산화제로서는 1970년대까지 사용되었다. 1990년대에 들어서 저비용, 친환경적인 개발이 중요하게 대두되면서 과산화수소는 다시 개발자들의 관심의 대상이 되었다. 과산화수소의 저장성능이 과거에 비해 크게 개선되었으며, 케로신/과산화수소를 추진제 조합으로 사용하는 경우 케로신/액체산소를 사용하는 경우에 비하여 가속성능은 다소 떨어지나, 높은 추진제밀도와 O/F 비로 인하여 유사한 가속성능을 얻을 수 있으며, 연소생성물 역시 더욱 청정하였다.

• 대한화학회지
• /
• 제37권2호
• /
• pp.199-205
• /
• 1993

구리-아민류착물에 의한 과산화수소의 초기분해속도를 pH7.3~11.8 범위에서 측정하였다. 과산화수소의 분해속도는 pH에 따라 증가하였다가 감소하였다. 이들 실험결과에 일치하는 가능한 메카니즘이 제안되었다. 이 메카니즘은 과산화수소와 구리-아민류착물의 탈양성첨가를 거친 다음에 속도 결정단계에서 퍼옥소구리착물이 생성되는 반응과정과 일치한다.

• 한국대기환경학회지
• /
• 제16권1호
• /
• pp.61-68
• /
• 2000

Gas-phase hydrogen peroxide(H2O2) concentrations were measured to investigate it's distribution in the ambient air in downtown Seoul(Kwanghwamum and Mullae-dong). These measurements were made during four season, from April 30, 1998 to January 29, 1999, using Cold Trap and HPLC. Measurements were also made of other photochemical oxidants and trace gases(O3, NO2, CO and SO2) and meteorological parameters(relative humidity, temperature, solar radiation and wind speed). The mean of all observations was 0.10 ppbv and the range measured was below the level of detection(>0.01 ppbv) to 0.47ppbv. The higher seasonal mean concentrations showed during the summer(0.21 ppbv) and concentrations of H2O2 showed a diurnal variation with maximum concentrations in the afternoon(12:30∼14:00). The results from the corrrelation analysis showed that the concentration of gaseous H2O2 is strongly dependent on the other air pollutants(NO2, CO and O3) and meteorological parameters(relative humidity, temperature and solar radiation.)