Photocatalytic Hydrogen Production by Utilizing Solar Energy

	Photocatalytic Hydrogen Production by Utilizing Solar Energy
	Li C(李灿)
	2011
会议名称	the royal society discussion meeting
会议日期	2011-11-14
会议地点	london
页码	10-0
通讯作者	李灿
中文摘要	this lecture presents the photocatalytic hydrogen production by utilizing solar energy, mainly discussing three types of reactions including water splitting, biomass reforming and industrial waste reforming. hydrogen molecule is an energy carrier for solar energy storage, and is ideal for clean energy process, and the hydrogen production utilizing solar energy could eventually realize the so called hydrogen economy and as a means for solar energy powering the world. the bottleneck to produce hydrogen through photocatalysis is the developing of high active photocatalysts which have been extensively investigated and explored during last several decades. this talk will focus on the role of cocatalysts in photocatalysis. the crucial roles of dual co-catalysts respectively for both half reactions, oxidation and reduction are highlighted. three typical catalysts, pt/tio2, pt-pds/cds and copi/bivo4 are studied for methanol reforming (as a representative reaction of biomass reforming), h2s reforming and water splitting reaction respectively. our research shows that the cocatalyst is necessary for hydrogen evolution or/and oxygen evolution, and the coloading of dual co-catalysts are absolutely necessary for improving the photocatalytic activity by reducing the recombination of photogenerated electrons and holes and reducing the activation energy. it is found that the oxidation half reaction is the most difficult part of the photocatalytic hydrogen production, particularly from water splitting reaction, and the cocatalyst to reduce the activation energy for oxygen evolution from water splitting essentially acts as the same role as the electrochemical catalysts to lower the overpotential. by well designing and loading the dual cocatalysts, pt and pds on cds, using na2s+na2so3 (h2s dissolved in naoh) as sacrificial reagent, we can achieve a quantum efficiency of the artificial photosynthesis high as 93%. in situ photoelectrochemical measurements, photoluminescence spectroscopy and high resolution transmission electron microscopy characterizations indicate that the exceptionally high quantum efficiency can be attributable to the vital factors including mainly the spatially separated pds and pt as the oxidation and reduction active sites respectively; the efficient utilization of the electrons at the shallow trap states of cds for photocatalytic reactions; and the formation of atomic heterojunctions between the co-catalyst pds and cds as these factors could effectively prohibit the recombination of photogenerated electrons and holes and favor the full utilization of the photogenerated electrons.
合作状况	特邀报告
会议主办者	the royal society
会议录	discussion meeting on can solar power deliver?
会议录出版者	待补充
会议录出版地	待补充
学科主题	物理化学
内容类型	会议论文
源URL	[http://159.226.238.44/handle/321008/116093]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
推荐引用方式 GB/T 7714	Li C. Photocatalytic Hydrogen Production by Utilizing Solar Energy[C]. 见:the royal society discussion meeting. london. 2011-11-14.