Unusual aliovalent Cd doped γ‐Bi₂MoO₆ nanomaterial for efficient photocatalytic degradation of sulfamethoxazole and rhodamine B under visible light irradiation

Abstract

Due to γ‐Bi2MoO6 (BMO) has attracted considerable attention because of its unique layered perovskite structure and excellent electrical conductivity. However, the easy recombination of electron–hole pairs limits its practical application. To address this issue, we successfully prepared aliovalent Cd2+ doped BMO (Cd‐BMO) by using a simple hydrothermal method for the degradation of the sulfamethoxazole (SMZ) and Rhodamine B (RhB). The result found that the degradation efficiency of Cd‐BMO is significantly higher than that of BMO, despite an increase in the bandgap after the introduction of Cd2+. The superior degradation efficiency of 8% Cd‐BMO, with a smaller particle size and larger specific surface area, can be attributed to its fast charge separation efficiency, low charge transfer resistance, and low rate of electron–hole pair recombination. Repeated and ion spillover experiments prove that 8% Cd‐BMO shows good stability and environmental protection. Theoretical simulation demonstrates that Cd offers electrons to the BMO system due to the decreased binding energy of BMO. The 8% Cd‐BMO sample can provide a suitable electric band edge for generating dominant active radicals during degradation. This work not only provides a potential candidate of 8% Cd‐BMO for practical degradation but also sheds light on the design of superior photocatalysts.

Recent progress in defect‐engineered metal oxides for photocatalytic environmental remediation

“…Notably, the photo-response intensity for 8% Cd-BMO exhibits a rise, suggesting that Cd-BMO has the capacity to produce a greater number of photoinduced pairs of electrons and holes, hence facilitating the advancement of photocatalytic events. 375 The degradation efficiency of 8% Cd-BMO shows the highest activity with SMZ (97.9%) in 210 min and RhB (97.8%) in 70 min. The degradation mechanism of the catalyst is shown in Figure 16E.…”

“…The XRD pictures of Cd-BMO for various doping ratios do not exhibit any noticeable additional diffraction peaks, suggesting that the addition of Cd 2+ ions does not modify the crystal structure of BMO. 375 It was noted that diffraction peak corresponding to 131 plane shifted to larger 2θ values which revealed the shrinkage of the lattice (Figure 16D). The structure and morphology of BMO were unaltered after successful doping with Cd 2+ which was further confirmed by the SEM analysis.…”

“…376 Cd-doping strategy in γ-Bi 2 MoO 6 (BMO) (Figure 16C) was used by Zhang et al for effective and efficient photocatalytic degradation of drug sulfamethoxazole (SMZ) and RhB. 375 The catalyst was synthesized by a simple hydrothermal approach and the findings indicate that although there was an increase in bandgap (2.73-2.86 eV) following the addition of Cd 2+ , the degrading efficiency of Cd-BMO is substantially higher compared to BMO. 8% Cd-BMO exhibits better degrading efficacy because of its low charge transfer resistance and quick charge separation efficiency, as it has a greater specific surface area and smaller particle size.…”

“…The specific surface area of BMO increases from 4.334 to 15.151 m 2 g −1 with Cd 2+ ion doping, suggesting that the doping of Cd 2+ ions increases the specific surface area of the BMO structure. 375 These more active sites enhance the capacity for photocatalysis and electrical conductivity. Furthermore, the optical analysis revealed that the absorption band edge shifts to higher wavelength upon Cd doping which indicates enhanced visible light absorption in Cd-BMO.…”

First-Principles Study of Electronic Structure and Optical Properties of Ni-Doped Bi4O5Br2

“…These materials have encountered limitations related to band gaps, light absorption ranges, and electron-hole recombination during photocatalysis [16,17]. Researchers have employed diverse strategies to address these challenges, including constructing heterojunctions, loading materials to inhibit electron-hole recombination, and doping to modify the energy band structure [18][19][20][21][22]. Among these approaches, doping stands out as the simplest and most effective method [23][24][25].…”