Saira Farhat, Saleemi Samia, Razzaq Humaira, Qureshi Rumana
Nanoscience and Technical Division, National Centre for Physics (NCP), Islamabad Pakistan.
Department of Chemistry, Quaid-i-Azam University, Islamabad Pakistan.
Turk J Chem. 2021 Feb 17;45(1):82-91. doi: 10.3906/kim-2004-52. eCollection 2021.
Spectrophotometric monitoring of 4-nitrophenol (4-NP) reduction by sodium borohydride (NaBH) using gold nanoparticles (GNPs) as a catalyst has been extensively studied, but the stability of GNPs in terms of change in the surface plasmon resonance (SPR) at different temperatures has not been explored. In the present investigation, our aim was to evaluate the SPR stability of GNPs as a catalyst during the reduction of 4-NP at different elevated temperatures (i.e. 30-60 °C) and sodium borohydride concentrations. Sensitivity of this degradation process toward concentration of GNPs at a range of temperatures is also evaluated. The spectrophotometric results reveal that up to 45 °C, 12 ± 1.5 nm catalyst has a consistent optical density (OD) during the entire 4-NP reduction process, which is related to the surface integrity of catalyst atoms. As the temperature approached 50 °C, the OD gradually decreased and showed a blue shift as the reaction proceeded, which could be related to a decrease in particle size or surface dissolution of gold atoms. The present study may find application in the design of catalysts for the reduction of organic pollutants in industrial wastewater at a range of temperatures.
利用金纳米颗粒（GNPs）作为催化剂，通过硼氢化钠（NaBH）还原4-硝基苯酚（4-NP）的分光光度监测已得到广泛研究，但尚未探讨不同温度下GNPs在表面等离子体共振（SPR）变化方面的稳定性。在本研究中，我们的目的是评估在不同升高温度（即30 - 60°C）和硼氢化钠浓度下，GNPs作为催化剂在还原4-NP过程中的SPR稳定性。还评估了该降解过程在一系列温度下对GNPs浓度的敏感性。分光光度结果表明，在高达45°C时，12±1.5 nm的催化剂在整个4-NP还原过程中具有一致的光密度（OD），这与催化剂原子的表面完整性有关。当温度接近50°C时，OD逐渐降低，并且随着反应进行出现蓝移，这可能与粒径减小或金原子的表面溶解有关。本研究可能在设计用于在一系列温度下还原工业废水中有机污染物的催化剂方面找到应用。
