• 대한화학회지
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• 제57권4호
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• pp.483-488
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• 2013

$CuCl_2$로부터 용액합성법에 의해 CuO를 제조하였다. $CuCl_2$를 용액에 첨가하기 전에 용액내에 anatase형 $TiO_2$ 입자를 분산시켜 CuO가 형성되는 과정에서 $TiO_2$/CuO 결합입자를 합성하였다. 얻어진 $TiO_2$/CuO에 적당량의 글루코스를 가하여 반응시켜 CuO의 일부를 $Cu_2O$로 환원시켰다. 얻어진 시료 $TiO_2/Cu_xO$ (1$TiO_2/Cu_xO$ 복합체는 anatase와는 다르게 가시광선 전 영역에서 흡광이 발생했으며 당연한 결과로 태양광선에서 $TiO_2/Cu_xO$ 복합체의 광촉매 활성은 anatase $TiO_2$에 비하여 매우 뛰어난 것으로 나타났다. 또한 $TiO_2/Cu_xO$ 복합체의 항균성이 대단히 뛰어난 것으로 나타났다.

• 한국환경과학회지
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• 제28권11호
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• pp.971-981
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• 2019

This study evaluated the photocatalytic oxidation efficiency of volatile organic compounds by $Cu_2O-TiO_2$ under visible-light irradiation. $Cu_2O-TiO_2$ was synthesized by an ultrasonic-assisted method. The XRD result indicated successful p-n type photocatalysts. However, no diffraction peaks belonging to $TiO_2$ were observed for the $Cu_2O-TiO_2$. The Uv-vis spectra result revealed that the synthesized $Cu_2O-TiO_2$ can be activated under visible-light irradiation. The FE-TEM/EDS result showed the formation of synthesized nanocomposites in the commercial P25 $TiO_2$, the undoped $TiO_2$, and $Cu_2O-TiO_2$ and componential analysis in the undoped $TiO_2$ and $Cu_2O-TiO_2$. The photocatalytic oxidation efficiencies of benzene, toluene, ethylbenzene, and o-xylene with $Cu_2O-TiO_2$ were higher than those of P25 $TiO_2$ and undoped $TiO_2$. These results indicate that the prepared $Cu_2O-TiO_2$ photocatalyst can be applied effectively to control gaseous BTEX.

• 한국물환경학회지
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• 제21권1호
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• pp.84-91
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• 2005

$TiO_2-catalyst$ suspensions work efficiently in Photocatalytic oxidation (PCO) for wastewater treatment. Nevertheless, once photocatalysis is completed, separation of the catalyst from solution becomes the main problem. The PCO of Cu(II)-EDTA was studied to determine the reusability of the titanium dioxide catalyst. Aqueous solutions of $10^{-4}M$ Cu(II)-EDTA were treated using illuminated $TiO_2$ particles at pH 6 in a circulating reactor. $TiO_2$ was reused in PCO system for treatment of Cu(II)-EDTA comparing two procedures: reuse of water and $TiO_2$ and reuse of the entire suspension after PCO of Cu(II)-EDTA. The results are as follows; (i) Photocatalytic efficiency worsens with successive runs when catalyst and water are reused without separation and filtration, whereas, when $TiO_2$ is separated from water, the reused $TiO_2$ is not deactivated. (ii) The $TiO_2$ mean recovery (%) with reused $TiO_2$ was 86.4%(1.73g/L). Although the mean initial degradation rate of Cu(II)-EDTA and Cu(II) was lower than that using fresh $TiO_2$, there was no significant change in the rate during the course of the three-trial experiment. It is suggested that Cu(II)-EDTA could be effectively treated using an recycling procedure of PCO and catalyst recovery. (iii) However, without $TiO_2$ separation, the loss of efficiency of the PCO in the use of water and $TiO_2$ due to Cu(II), DOC remained from previous degradation and Cu(II)-EDTA added to the same suspension was observed after 2 trials, and resulted in the inhibition of the Cu(II)-EDTA, Cu(II) and DOC destruction.

• 한국환경과학회지
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• 제29권12호
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• pp.1213-1222
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• 2020

In the current study, a Cu2O/TiO2 photoinduced nanocomposite materials prepared by ultrasonification method was evaluated the photocatalytic oxidation efficiency of volatile organic compounds (BTEX) under visible-light irradiation. The results of XRD confirmed the successful preparation of photoinduced nanocomposite materials. However, diffraction peaks belonging to TiO2 were not confirmed for the Cu2O/TiO2. The possible reason for the absence of Cu2O peak is their low content and small particle size. The result of uv-vis spectra exhibited that the fabricated Cu2O/TiO2 can be activated under visible light irradiation. The FE-SEM/EDS and TEM showed the formation of synthesized nanocomposites and componential analysis in the undoped TiO2 and Cu2O/TiO2. The photocatalytic oxidation efficiencies of benzene, toluene, ethylbenzene, and o-xylene with Cu2O/TiO2 were higher than undoped TiO2. According to light sources, the average oxidation efficiencies for BTEX by Cu2OT-0.5 were exhibited in the orer of 8 W day light > violet LEDs > white LEDs. However, the photocatalytic oxidation efficiencies normalized to supplied electric power were calculated to be in the following order of violet LEDs > white LEDs > 8 W day light, indicating that the LEDs could be a much more energy efficient light source for the photo-oxidation of gaseous BTEX using Cu2O/TiO2.

• 한국산학기술학회논문지
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• 제17권7호
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• pp.713-719
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• 2016

암모니아를 환원제로 사용하는 선택적 촉매 환원법에서 Mn-Cu-$TiO_2$ 촉매와 $V_2O_5$/$TiO_2$ 촉매를 사용하여 반응 조건에 따른 질소 산화물 전환 특성을 연구하였다. 반응 온도와 공간 속도를 변경시키면서 촉매의 질소 산화물 전환 효율 변화를 측정하였다. Mn-Cu-$TiO_2$ 촉매의 질소 산화물 제거 활성은 반응 온도와 공간 속도가 증가할수록 감소하였으나, $V_2O_5$/$TiO_2$ 촉매의 경우 반응 온도 증가에 따라 촉매의 질소 산화물 제거 활성 또한 증가하였다. Mn-Cu-$TiO_2$ 촉매의 경우 $200^{\circ}C$ 이하의 온도에서 저온 활성이 우수하였으며, 이를 $H_2$-TPR 및 XPS 분석 실험을 통해 확인할 수 있었다. 초기 반응 온도의 변경 실험을 통해 Mn-Cu-$TiO_2$ 촉매의 경우 고온에서 열적 쇼크를 일부 받으나, $V_2O_5$/$TiO_2$ 촉매의 경우는 거의 영향을 받지 않음을 확인할 수 있었다. 공간 속도에 따른 질소 산화물 전환 효율 변화는 C 촉매의 경우 전 구간에 걸쳐 공간 속도가 증가할수록 질소 산화물 전환 효율도 감소하는 경향을 보였다. 그러나 D 촉매의 경우 공간 속도가 증가할수록 질소 산화물 전환 효율은 감소하였으나, 감소 정도가 C 촉매 보다는 훨씬 적었다.

• 한국재료학회지
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• 제14권4호
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• pp.246-250
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• 2004

We have investigated the effects of boron added to Cu film on the Cu-Ti reaction and microstructural evolution of Cu(B) alloy film during annealing of Cu(B)/Ti/$SiO_2$/Si structure. The result were compared with those of Cu(B)/$SiO_2$ structure to identify the effects of Ti glue layers on the Boron behavior and the result grain growth of Cu(B) alloy. The vacuum annealing of Cu(B)/Ti/$SiO_2$ multilayer structure allowed the diffusion of B to the Ti surface and forming $TiB_2$ compounds at the interface. The formed $TiB_2$ can act as a excellent diffusion barrier against Cu-Ti interdiffusion up to $800^{\circ}C$. Also, the resistivity was decreased to $2.3\mu$$\Omega$-cm after annealing at $800^{\circ}C$. In addition, the presence of Ti underlayer promoted the growth Cu(l11)-oriented grains and allowed for normal growth of Cu(B) film. This is in contrast with abnormal growth of randomly oriented Cu grains occurring in Cu(B)/$SiO_2$ upon annealing. The Cu(B)/Ti/$SiO_2$ structure can be implemented as an advanced metallization because it exhibits the low resistivity, high thermal stability and excellent diffusion barrier property.

• 한국재료학회지
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• 제14권12호
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• pp.829-834
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• 2004

Annealing of $Cu(B)/Ti/SiO_2$ in vacuum has been carried out to investigate the effects of Ti underlayer on microstructure in $Cu(B)/Ti/SiO_2$ structures. For comparison, $Cu(B)/Ti/SiO_2$ structures was also annealed in vacuum. Three different temperature dependence of Cu growth can be seen in $Cu(B)/Ti/SiO_2$; B precipitates- pinned grain growth, abnormal grain growth, normal grain growth. The Ti underlayer having a strong affinity for B atoms reacts with the out-diffused B to the Ti surface and forms titanium boride at the Cu-Ti interface. The formation of titanium boride acts as a sink for the out-diffusion of B atoms. The depletion of boron in grain boundaries of Cu films, as results of the rapid diffusion of B along the grain boundaries and the insufficient segregation of B to the grain boundaries, induces grain boundaries to migrate and causes the abnormal grain growth. The increased bulk diffusion coefficient of B within Cu grains can be responsible for the normal grain growth occurring in the annealed $Cu(B)/Ti/SiO_2\;at\;600^{\circ}C$. In contrast, the $Cu/SiO_2$ structures show only the abnormal growth of grains and their sizes increasing as the temperature increases above $400^{\circ}C$.

• 한국전기전자재료학회논문지
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• 제28권2호
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• pp.80-84
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• 2015

We investigated the dielectric relaxation properties $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics with CuO addition. With increasing CuO addition, the lattice parameter was increased by substitution of small amount $Cu^{2+}$ ion in B-site of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics. Also the grain size and the maximum dielectric constant of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics was decreased with increasing amounts of CuO addition. Moreover, the diffused phase transition properties (${\gamma}$) of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics was increased by compositional fluctuation with increasing of CuO amount, changed from 1.45 at 1 wt% CuO addition to 1.94 at 7 wt% CuO addition.

• 대한환경공학회지
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• 제27권8호
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• pp.844-851
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• 2005

본 연구의 목적은 $TiO_2$를 이용한 Cu(II)-EDTA 광촉매 반응 후의 $TiO_2$를 재사용 흑은 재생함으로써 연속적인 광산화 반응에 적용할 수 있는 타당성을 조사하기 위해 총 8회에 걸친 연속 광산화반응에서의 구리 및 $TiO_2$의 회수율과 처리수내의 상대급성독성을 평가하였다. 순환형의 회분식 광산화반응장치를 사용하고 pH 6 조건에서 인공자외선 조사에 의한 $10^{-4}\;M$ Cu(II)-EDTA의 광촉매 산화반응을 실시하였으며 두가지의 $TiO_2$ 재이용방법을 사용하였다: i) 산세척하지 않고 $TiO_2$ 재이용, ii) 산세척 후의 $TiO_2$ 재이용. 산세척하지 않고 $TiO_2$ 재이용시, Cu(II)-EDTA의 분해속도상수($k'_{obs}$) 평균은 산세척 후의 $TiO_2$ 재이용시의 $k'_{obs}$ 평균값 보다 약 45% 적게 나타났다. 산세척 후 $TiO_2$를 재이용한 경우, 총 8회 재이용 실험 모두에서 180분 이후에는 거의 완전한 Cu(II)의 제거가 일어났지만 산세척하지 않고 $TiO_2$를 재이용하였을 때에는 총 5회 재이용시에 Cu(II)가 최소로 제거되었다. 두 재이용 방법 모두 총 8회에 걸친 $TiO_2$의 평균 회수율은 약 86%로 나타났으며 산세척시의 구리회수율은 67.9%가 되었다. 산세척 후의 $TiO_2$ 재이용시 반응시간 60분 까지의 초기 반응시간 대에는 처리수내의 상대독성이 급격히 감소하였지만 60분 이후에는 독성의 저감이 크게 감소하였다. 산세척 없이 $TiO_2$를 재이용하였을 때에는 상대독성의 경향은 용존 구리이온과 관계있는 것으로 나타났다. 본 연구를 통해 $TiO_2$ 및 구리를 회수하는 연속 순환공정을 적용함으로써 Cu(II)-EDTA의 효율적인 제거 가능성을 제안할 수 있었다.

• 한국분말재료학회지
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• 제9권2호
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• pp.110-115
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• 2002

In order to obtain the nano size $10wt%Cu-TiO_2$composite powders by mechanical alloying method for useful composite catalysis, the effects of mechanical alloying time on the formationof $10wt%Cu-TiO_2$ composite powders were analyzed. The phase transformation behaviors were experimented as the heat treating temperature increased. Homogeneous 10wt% Cu-rutile type $TiO_2$composite powders were synthesized in 40 hours by mechanical alloying. After 60 hours mechanical alloying 50 nm size $TiO_2$powders were obtained. Both the phase of mechanically alloyed 10 wt% $Cu-TiO_2$ and pure $TiO_2$ powders were not transformed to anatase after annealing at the temperature range between 350 to 500 $^{\circ}C$. The intermetallic compound of $Cu_2Ti_4$O was formed after 10 hours mechanical alloying, however it could be considered that this intemetallic phase dose not prevent the transformation of rutile $TiO_2$ to the anatase phase after heat treatment at the temperature between 350 and $550^{\circ}C$.