High activity of hot electrons from bulk 3D graphene materials for efficient photocatalytic hydrogen production

Design and synthesis of efficient photocatalysts for hydrogen production via water splitting are of great importance from both theoretical and practical viewpoints.Many metal-based semiconductors have been explored for this purpose in recent decades.Here,for the first time,an entirely carbon-based material,bulk three-dimensionally cross-linked graphene (3DG),has been developed as a photocatalyst for hydrogen production.It exhibits a remarkable hydrogen production rate of 270 μmol·h-1·g-1cat under full-spectrum light via a hot/free electron emission mechanism.Furthermore,when combined with the widely used semiconductor TiO2 to form a TiO2/3DG composite,it appears to become a more efficient hydrogen production photocatalyst.The composite achieves a production rate of 1,205 μmol·h-1.g-1cat under ultraviolet-visible (UV-vis) light and a 7.2％ apparent quantum efficiency at 350 nm due to the strong synergetic effects between TiO2 and 3DG.     

燃煤电厂脱硫废水辅助煤电解制氢

燃煤电厂脱硫工艺产生的脱硫废水具有高盐分、腐蚀性和结垢性等特点,是电厂废水处理中最难的一个环节。基于H型电解池对脱硫废水及其辅助煤电解的特性进行了研究,在脱硫废水资源化利用的同时吸纳燃煤电厂的过余电力。结果表明：脱硫废水经过酸化后电解性能明显高于水,可以降低电解制氢的电耗;仅脱硫废水不能促进煤的电氧化,仍需要添加部分铁离子作为催化剂,但未经酸化的脱硫废水可以促进铁离子的催化作用,从而进一步降低电解制氢的电耗。基于此,提出了酸化处理、直接利用和添加煤粉3种可能的电解脱硫废水制氢的工艺手段。