Mechanisms and Applications of Photocatalytic Reactions in the Gas Phase

光催化远程氧化和光催化光刻的主要机理是：在光催化剂上生成的过氧化氢在气相中扩散，然后光解生成活性物质羟基自由基。将光催化光刻技术应用于多通道生物传感器阵列的研制。针对具有氧化还原活性固体的光催化剂之间的电子交换以及在储能型光催化剂中的应用，研究了TiO_2向WO_3和MoO_3的光诱导电子转移和质子输运。研究了还原性储能的量子效率和容量以及吸附水对储能的影响。发现Ni(OH)_2在光激发TiO_2中有可能向空穴转移电子。TiO_2-Ni(OH)_2复合薄膜作为氧化储能光催化剂。即使在天黑后，它也应该能够去除甲醛等一些有害化合物。Ir氧化物和Ru氧化物作为氧化储能材料表现出较高的氧化能力。在金属纳米粒子-半导体体系的等离子体光电化学研究中，发现了银纳米粒子- tio_2体系的多色光致变色现象。在光致变色的机理研究中，发现金属纳米颗粒-半导体界面处的光致电荷分离起着至关重要的作用。电荷分离过程可应用于光催化和太阳能电池。实验证明，与入射光共振的银纳米粒子的光电溶解和非共振银纳米粒子的沉积和生长是导致光谱变化的原因。开发了金纳米结构，发现纳米金字塔具有宽的等离子体共振带。光电化学致动器，其膨胀和收缩响应光。基于藻类趋光性的生物传感器也被开发出来。

Major mechanisms of photocatalytic remote oxidation and photocatalytic lithography were revealed to be as follows: hydrogen peroxide generated on a photocatalyst diffuses in the gas phase, followed by photolysis to hydroxyl radicals, which are the active species. Photocatalytic lithography was applied to development of multichannel biosensor arrays.Regarding electron exchange between a photocatalyst with redox-active solids and the application to energy storage photocatalysts, photo-induced electron transfer and proton transport from TiO_2 to WO_3 and MoO_3 were studied. Quantum efficiencies and capacities of the reductive energy storage and effects of adsorbed water on the energy storage were studied. It was found that electron transfer is possible from Ni(OH)_2 to holes in photo-excited TiO_2. A TiO_2-Ni(OH)_2 composite film works as an oxidative energy storage photocatalyst. It should be able to remove some harmful compounds such as formaldehyde even after dark. An Ir oxide and a Ru oxide exhibit higher oxidation abilities as oxidative energy storage materials.Regarding plasmon photoelectrochemistry of metal nanoparticles-semiconductor systems, multicolor photochromism of Ag nanoparticles-TiO_2 systems was found. In the mechanistic study of the photochromism, it was found that photo-induced charge separation at the metal nanoparticle-semiconductor interface plays an essential role. The charge separation process can be applied to solar cells and photocatalysis. I was evidenced that photoelectrochemical dissolution of Ag nanoparticles resonant with an incident light and deposition and growth of non-resonant Ag nanoparticles are responsible for the spectral changes.Au nanostructures were developed and nanopyramids were found to exhibit a broad plasmon resonance band. Photoelectrochemical actuators, which swell and shrink in response to light were developed. Biosensors based on algal phototaxis were also developed.