Sodium sulfite and sodium sulfide can generate hydrogen under ultraviolet light, and their hydrogen production is very high compared with other sacrificial agents. On the other hand, if visible under 420nm, there will be basically no. Therefore, if the use of full spectrum or ultraviolet light as a photocatalyst for the use of this sacrificial agent is not reasonable, we should deduct the amount of hydrogen production I of the sacrificial agent in the blank experiment. If the photocatalytic experiment is done under visible light, it will have little effect. Generally speaking, methanol and silver nitrate are better electron donors and electron acceptors.