The Study Of Carbon Modified BiVO₄ For The Degradation Of Organic Contaminant Under Visible Light Irradiation

In recent years, the serious environmental problems caused by organic in water are more and more serio us. In this paper, we have studied the activity of carbon modified Bi VO 4 and degradation of phenol by adding electronic capture agent synergy carbon modified Bi VO 4, systematically.In-situ carbon loaded Bi VO 4were obtained by impregnation calcination method. The results of characterization showed that in-situ carbon loading didn't changed the monoclinic crystal structure of Bi VO4, but the crystalline of Bi VO4 weakened gradually and the surface became rough. Moreover, with the increase of carbon rings and loa ds, the specific surface area and the separation of electron-hole pairsincreased. The carbon loads promoted the visible light absorption.The experiment showed that the activity increasedwith the increase of number of carbon rings at the same loads, and with the increase of carbon loads at the same carbon source, the activity increased firstly and then decreased. Thereinto, with cellulose as the source, 0.5 wt. % of in-situ carbon loaded Bi VO 4 had the highest activity with 88.7% ofphenol removal rate.The effect of calcination temperature of in-situ carbon modified Bi VO 4 was studied. The results of characterization showed that the catalyst keep monoclinic crystal phase with th e calcination temperature of 400?-600?.But when the calcination temperature were 700? and 800?, the phase was changed and its surfacebecame rough. With the increase of calcination temperature, the crystallinity, specific surface area and separation of the electron-hole pairs of catalyst increased first ly and then decreased, which was the best at 500?. While the visible light absorption of catalyst increased gradually. The experiment showed that with the increase ofcalcination temperature, the catalyst activityincreased at first and then decreased, which was highest at 500?.Graphene loaded Bi VO4 were obtained by hydrothermal method. The results of characterization showed that graphene loading didn 't change the monoclinic crystal structure of Bi VO 4, but the crystalline of Bi VO 4 weakened gradually. With the decrease of graphene size and the in crease of loads, the specific surface area and separationof the electron-hole pairsof catalyst increased at first and then decreased, which was the largest when the size was 5-7 ?m and the loads was 0.5 wt.%. Moreover, the addition of graphene had a certain effect on the morphology of catalyst, which with the decrease of size and the increase of loads of graphene, Bi VO 4 were wrapped gradually. With the decrease of graphene size an d increase of graphene loads, the visible light absorption of catalyst enhanced gradually. The experiment showed that with the decrease of size and the increase of graphene loads, the activity increased firstly and then decreased. When the size was 5-7?m and the load was 0.5 wt.%, the graphene modified Bi VO 4 photocatalyst had the highest activity with 65.2% of phenol removal rate.The optimum catalyst synergy with electron capture agent KBr O 3was used to degrade phenol. When the catalyst dosage was 1 g/L, p H value was 3 and KBr O3 dosage was 25 mmol/L, the removal rate was highest. The degradation rates of 1000 mg/L phenol were 52.3% and 47.6% after irradiating 5 h under Xe-lamp and sunlight, respectively.