Effective promotion of g-C3N4 photocatalytic performance via surface oxygen vacancy and coupling with bismuth-based semiconductors towards antibiotics degradation

In this research, the potential of bismuth chromate (BCO), a new bismuth-based semiconductor belongs to the family of Bi2XO6 (X = Mo, W, or Cr), was introduced by a novel 1D/2D structure consist of BCO nanobelts and N2- freezed ultra-wrinkled graphitic carbon nitride (N-CN) nanosheets. To enhance intimate contact between BCO and N-CN (BCO/N-CN composite), surface oxygen vacancy (V-O) was created as an efficient electron transfer highway using a simple alkaline-treatment-assisted method. Various characterization techniques, including XRD, FT-IR, EPR, FE-SEM, TEM, BET, DRS, PL, EIS, and photocurrent transient analyses were conducted to elucidate the physicochemical aspects of catalysts. The synthesized catalysts were subjected to levofloxacin (LVFX) photo degradation and optimum conditions were found under LED irradiation. Under optimum conditions, about 92.5% of LVFX was catalytically degraded over V-O-rich BCO/N-CN heterojunction after 120 min of reaction, which was 2.3 folds higher than that of V-O-free composite. The obtained heterojunction maintained superior performance after five consecutive runs with no noticeable changes in the XRD and FT-IR patterns, demonstrating the high stability of synthesized nanocomposite. Thus, the proposed interfacial engineering in this study opens new insight for ameliorating the insufficient interfacial contact between components of heterojunctions. This study not only presents a new bismuth-based photocatalyst for antibiotic degradation but also sheds light on the charge migration behavior in favor of efficient Z-type heterojunction.

Automated summary

In this research, a novel BCO/N-CN composite was synthesized by introducing a new 1D/2D structure and creating surface oxygen vacancy (V-O) to serve as an efficient electron transfer highway. The composite showed excellent catalytic performance in the photodegradation of levofloxacin (LVFX) and maintained high stability over multiple reaction cycles. This study provides new insights into improving interfacial contact between components of heterojunctions and sheds light on charge migration behavior for efficient Z-type heterojunctions.