光敏络合催化光解水析氢的电化学模拟

Durham等^[1]曾利用Pt(黑)|lN HCl‖Ru(bipy)₃²⁺、MV²⁺、EDTA(pH=9)|Pt(网)电池模拟光解水析氢反应。但该装置的左、右二半电池中溶液的pH值相差9以上,相当于外加0.5V以上的偏压,因此,不能真实地模拟自发的光解水析氢过程。

ELECTROCHEMICAL SIMULATION OF HYDROGEN PRODUCTION BY PHOTOLYSIS OF WATER USING Ru-COMPLEX AS PHOTOSENSITIZER

A cell composed of Pt (black)|HAc +NaAc (pH = 4.7)||Ru(bipy)₃²⁺, MV²⁺, EDTA(pH = 4.7) | Hg was constructed to simulate the production o hydrogen by photolysis of water employing Ru(bipy)₃²⁺ as photosensitizer, MV²⁺ as electron-relay and EDTA as sacrificing electron doner. Using Hg as anode,on which the hydrogen overpotential is extraordinarily high, we had been able to obtain short-circuit current under condition that solutions in both half cells were of the same pH value.Therefore,disadvantages caused by using Pt as anode and by solutions of different pH value (as in[4],[4a] ) were avoided. In other words,we had succeeded in simulating the spontaneous process of photogeneration of hydrogen with an electrochemical cell,thus varified experimentally the pathway of electron transfer in such system. Main factors governing the magnitude of short-circuit current were found to be the rate of transfer of MV²⁺ from bulk of solution to electrode surface and the electrocatalytical behavior of cathode.