The nest-like bismuth-containing precursor was prepared by hydrothermal method with sodium gluconate as auxiliaries.The effect of the hydrothermal temperature and reactant concentration on the morphology and composition of the prepared precursor were systematically studied,and the for-mation mechanism of the precursor was elucidated.Then,calcination of the precursor was carried out at 150℃～400℃,during which the precursor decomposed to Bi2O3.At the same time,the carbon generated by high-temperature carbonization of the gluconic acid involved in the skeleton of the precursor can in si-tu reduce Bi3+to Bi nanoparticles.The phase transition during calcination process can be described as:precursor→Bi/β-Bi2O3(150℃～280℃)→Bi/β-Bi2O3/α-Bi2O3(300℃～350℃)→Bi(400℃).The degradation of levofloxacin hydrochloride(LVFH)was used as a probe to evaluate the visible-light photocatalytic perfor-mance of the as-prepared Bi/β-Bi2O3 heterojunctions.Among others,the Bi/β-Bi2O3 heterojunction ob-tained at 280℃ exhibited the best visible-light photocatalytic activity,and the degradation rate of LVFH can reach 97.75％after 140 min of visible-light irradiation.Its superior photocatalytic performance was at-tributed to the nest-like hierarchical structure and the SPR effect of the in situ generated Bi-nanoparticles,which improved visible-light harvesting and promoted the separation of photogenerated carriers.In addi-tion,the Bi/β-Bi2O3 heterojunction photocatalyst showed good recyclable and reusable performance.
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