ABSTRACT
Production of hydrogen peroxide (H2O2) via in situ electrochemical water oxidation possesses great potential applications in the energy and environment fields. In this work, for the first time, we reported a C,N codoped TiO2 electrode for selective electrocatalytic water oxidation to produce H2O2 in an acidic electrolyte. An electrochemical anodic oxidation method combined with postcalcination in the presence of urea was applied to fabricate such a C,N codoped TiO2 electrode, which was evidenced by detail structural characterizations. The calcination temperature and urea atmosphere were found to play key roles in its catalytic performances; the optimized 600N sample exhibited an onset potential of 2.66 V (vs Ag/AgCl) and a Tafel slope of 51 mV dec-1 at pH 3. Under the optimal applied potential, the cumulative H2O2 concentration for this sample reached 0.29 µmol L-1 cm-2 h-1. More importantly, a simple recalcination strategy was developed to recover the deactivation electrode. This study proposed an efficient C,N codoped TiO2 electrode toward water oxidation to selectively produce H2O2 in the acidic electrolyte, which could be further used to in situ generate H2O2 for the energy- and environment-related fields with water as the precursor.
ABSTRACT
OBJECTIVE: To investigate the relation between the expression of tPA, MMP-2, MMP-9 and AEG-1 in the human brain tissue and the ethanol concentration under the acute alcohol poison, and to analyze the role of alcohol and trauma in the mechanism of death of subarachnoid hemorrhage. METHODS: Fifteen real cases were collected in this study. The brain tissues were researched by histological examination and the concentration of ethanol in heart blood were detected. The tPA, MMP-2, MMP-9 and AEG-1 in brainstem, brain and cerebellum were observed respectively by immunohistochemistry. RESULTS: In alcohol poisoning groups with or without trauma, the acute alcohol toxicity resulted in the swelling of brain tissues. The tPA, MMP-2, MMP-9 and AEG-1 of brainstem, brain and cerebellum showed high expression in alcohol victims, and the tPA in cerebellum showed no difference. The expression of the MMP-2, MMP-9 and AEG-1 showed good relation with the ethanol concentration in blood (P < 0.05, r > 0.6). CONCLUSION: The expressions of tPA, MMP-2, MMP-9 and AEG-1 are significant higher in alcohol victims, and expressions of MMP-2 and MMP-9 and AEG-1 have positive correlation with the alcohol concentration. The alcohol has acute toxicity to brain cells.
