Enzyme electrodes that combine enzyme and electrode reactions have been applied to electrochemical sensors and biofuel cells. Advanced materials are required for efficient electron transfer between enzyme and electrode. This review article will describe the development of redox mediator, co-immobilization of enzyme and redox mediator on the electrode surface, porous carbon materials, and the effect of concentrated salts on enzyme electrode reactions.
Semiconductor quantum dots (QDs) are a class of low-dimensional nanomaterials, some of which can be obtained by colloidal synthesis methods. Unique phenomena occur when electrons are confined to a few nanometers of space, such as highly monochromatic emission and size-dependent wavelength shifts. Owing to the high ratio of surface atoms to the total number of atoms in QDs, not only the crystalline structure of the core, but also surface control is key to achieving high quality emission from QDs. Techniques such as the “hot injection” method, which can produce monodisperse nanoparticles with high crystallinity, and the “core/shell” structure, in which the core is coated with another wide bandgap semiconductor material to confine photoexcited excitons, have improved the emission properties of QDs to the point where they can be used in commercial displays. Efforts are underway to expand applications further by removing cadmium and incorporating QDs into electroluminescent devices. The emergence of various optical devices using these approaches is anticipated.
ポーラログラフィスト,電気化学者にとっては,金属を電極とした固|液界面,液(水銀)|液界面の電気化学については非常になじみ深いが,固体が金属から電気伝導度が何桁も減少する半導体に置き換わると,その界面での電気化学は半導体物性に詳しくないこともあり,よくわからないという人が多いのかもしれない。一方で,光電気化学の分野では電極材料に半導体を使うことで光励起による電子-正孔のキャリア生成をつかって興味ある特性を示す多くのデバイスが提案されている。また,全固体電池の固体と固体の界面は半導体|半導体界面,金属|半導体界面であり,この界面に発生した電位差がリチウムイオンの伝導に大きな影響を与えることが示唆されている。[1]
本シリーズでは,全文を4部にわけて報告する。2023年No1の本紙でPart Iとして「半導体の基礎」を報告した。[2] ここでは,Part IIでは「半導体中のポアソン-ボルツマン式」について述べる。シリーズの今後は,Part IIIで「半導体|電解質溶液の電気二重層」,Part IVで「金属|半導体界面 の電気二重層」について記述する。