초록문의 abstract@kcsnet.or.kr

결제문의 member@kcsnet.or.kr

현재 가능한 작업은 아래와 같습니다.
  • 09월 08일 17시 이후 : 초록수정 불가능, 일정확인 및 검색만 가능

제116회 대한화학회 학술발표회, 총회 및 기기전시회 안내 Highly Robust Hybrid Photocatalyst for Carbon Dioxide Reduction: Tuning and Optimization of Catalytic Activities of Dye/TiO2/Re(I) Organic-Inorganic Ternary Systems

2015년 9월 3일 16시 32분 15초
IND.P-95 이곳을 클릭하시면 발표코드에 대한 설명을 보실 수 있습니다.
10월 16일 (금요일) 13:00~14:30
저자 및
원동일, 이종수, 지정민, 정원조, 강상욱, 손호진*
고려대학교 소재화학과, Korea
Herein we report a detailed investigation of a highly robust hybrid system (sensitizer/TiO2/catalyst) for the visible-light reduction of CO2 to CO; the system comprises 5’-(4-[bis(4-methoxymethylphenyl)amino]phenyl-2,2’-dithiophen-5-yl)cyanoacrylic acid as the sensitizer and (4,4’-bis(methylphosphonic acid)-2,2’-bipyridine)ReI(CO)3Cl as the catalyst, both of which have been anchored on three different types of TiO2 particles, [001]-facet exposed nanosheets (S-TiO2) and two commercially available particulate materials (Hombikat and Degussa). The selective reduction of CO2 to CO was persistently catalyzed by visible-light irradiation of dispersions of the hybrid particles in N,N-dimethylformamide (DMF) at > 420 nm. The reduction efficiencies depended on the TiO2 sources, indicating that the catalytic activity of the hybrid system is significantly affected by the morphology, size, and agglomeration degree of the TiO2 particles. It was found that remarkable enhancements in the CO2 conversion activity of the hybrid photocatalytic system can be achieved by addition of water or such other additives as Li+, Na+, and TEOA. For a specific example studied, the photocatalytic CO2 reduction efficiency was enhanced by approximately 300% upon addition of 3% (v/v) H2O. To the best of our knowledge, the observed turnover number of CO formation (≥ 360), which was obtained from a single-run photoreaction, is the highest reported for heterogeneous catalytic systems. A series of Mott-Schottky (MS) analyses on nanoparticle TiO2 films demonstrated that the flat-band potential (Vfb) of TiO2 in dry DMF is substantially negative but positively shifts to considerable degrees in the presence of water or Li+, indicating that the enhancement effects of the additives on the catalytic activity should mainly arise from optimal alignment of the TiO2 Vfb with respect to the excited-state oxidation potential of the sensitizer and the reduction potential of the catalyst in our ternary system. The present results confirm that the TiO2 semiconductor in our heterogeneous hybrid system is an essential component that can effectively work as an electron reservoir and as an electron transporting mediator to play essential roles in the persistent photocatalysis activity of the hybrid system in the selective reduction of CO2 to CO.