Singh Sumit, Atri Amit Kumar, Qadir Irfan, Sharma Shikha, Manhas Ujwal, Singh Devinder
Department of Chemistry, University of Jammu, Jammu 180006, India.
ACS Omega. 2023 Feb 8;8(7):6302-6317. doi: 10.1021/acsomega.2c06249. eCollection 2023 Feb 21.
In the present paper, nanocrystalline samples of NiCrFeO were synthesized by the combustion method using different fuels such as glycine, urea, and poly(vinyl alcohol) and subjected to heat treatment at different temperatures of 600, 700, 800, and 1000 °C for 6 h. The formation of phases with highly crystalline structures was confirmed by XRD and Rietveld refinement analysis. The optical band gap of NiCrFeO ferrites lies in the visible range, making them suitable photocatalysts. BET analysis reveals that the surface area of the phase synthesized using PVA is much higher than that synthesized using other fuels at each sintering temperature. In addition, there is a significant decrease in the surface area with sintering temperature for the catalysts prepared using the fuels PVA and urea, while it almost remains constant in the case of glycine. Magnetic studies demonstrate the dependence of saturation magnetization on the nature of the fuel and on the sintering temperature; moreover, the coercivity and squareness ratio confirm the single domain nature of all the synthesized phases. We have also performed photocatalytic degradation of the highly toxic Rhodamine B (RhB) dye by employing all the prepared phases as photocatalysts using the mild oxidant HO. It is observed that the photocatalyst prepared using PVA as the fuel exhibited the best photocatalytic activity at all sintering temperatures. All the three photocatalysts prepared using different fuels showed a decrease in the photocatalytic activity with increasing sintering temperature. From the chemical kinetic point of view, the degradation of RhB by all the photocatalysts was found to follow pseudo-first-order kinetics.
在本论文中，采用燃烧法，使用甘氨酸、尿素和聚乙烯醇等不同燃料合成了NiCrFeO纳米晶样品，并在600、700、800和1000℃的不同温度下进行6小时的热处理。通过XRD和Rietveld精修分析证实了具有高结晶结构的相的形成。NiCrFeO铁氧体的光学带隙在可见光范围内，使其成为合适的光催化剂。BET分析表明，在每个烧结温度下，使用PVA合成的相的表面积远高于使用其他燃料合成的相。此外，对于使用燃料PVA和尿素制备的催化剂，其表面积随着烧结温度的升高而显著降低，而在甘氨酸的情况下几乎保持不变。磁性研究表明饱和磁化强度取决于燃料的性质和烧结温度；此外，矫顽力和矩形比证实了所有合成相的单畴性质。我们还使用温和氧化剂HO，将所有制备的相作为光催化剂，对剧毒罗丹明B（RhB）染料进行了光催化降解。观察到，使用PVA作为燃料制备的光催化剂在所有烧结温度下均表现出最佳的光催化活性。使用不同燃料制备的所有三种光催化剂的光催化活性均随烧结温度的升高而降低。从化学动力学角度来看，发现所有光催化剂对RhB的降解均遵循准一级动力学。
