Irfan Muhammad, Shah Afzal, Iftikhar Faiza Jan, Hayat Mazhar, Ashiq Muhammad Naeem, Shah Iltaf
Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
NUTECH School of Applied Science & Humanities, National University of Technology, Islamabad 44000, Pakistan.
ACS Omega. 2022 Sep 2;7(36):32302-32312. doi: 10.1021/acsomega.2c03641. eCollection 2022 Sep 13.
Textile industry effluents are heavily contaminated with dyes. The discharge of these toxic dyes into waterbodies poses a serious threat to aquatic flora and fauna. The ultimate entrance of these toxins from thereon into the food chain affects the primary and secondary consumers. Therefore, the adoption of a sustainable solution for protection against the detrimental effects associated with adulterated water is an immediate need of the hour. To address the severity of the issue, the present work aims to design an electrochemical sensing platform by modifying the glassy carbon electrode (GCE) with zinc oxide nanoparticles and amino group-functionalized multi-walled carbon nanotubes (NH-fMWCNTs) for the detection of Orange II, which is a toxic azo dye. Zinc oxide nanoparticles facilitate electron transfer between the transducer and the analyte. While, the positively charged NH-fMWCNTs in acidic medium help in preconcentration of negatively charged analyte molecules at the electrode/electrolyte interface. The modification of the GCE catalyzed the oxidation of Orange II, as evidenced by the negative shift of the oxidation potential and enhancement in peak current intensity. Square wave voltammetry was used to optimize various experimental conditions, such as the supporting electrolyte, pH of the electrolyte, deposition potential, and deposition time for the best performance of the designed sensor. Under the optimized conditions, the detection limit and quantification of the designed sensor were found to be 0.57 and 1.92 nM, respectively. The catalytic degradation studies of Orange II was shown to be facilitated by titanium dioxide, which acted as a photocatalyst. The addition of hydrogen peroxide further promoted the extent and rate of degradation of dye. The breakdown of Orange II was probed by the designed sensing platform electrochemically and also by UV-visible spectroscopy. The dye degraded up to 92% by following pseudo-first-order kinetics.
纺织工业废水被染料严重污染。这些有毒染料排放到水体中对水生动植物构成了严重威胁。这些毒素最终从水体进入食物链,影响初级和次级消费者。因此,当下迫切需要采用一种可持续的解决方案来防止受污染水带来的有害影响。为了解决该问题的严重性,本研究旨在通过用氧化锌纳米颗粒和氨基功能化多壁碳纳米管(NH-fMWCNTs)修饰玻碳电极(GCE)来设计一个电化学传感平台,用于检测有毒偶氮染料橙黄II。氧化锌纳米颗粒促进了传感器与分析物之间的电子转移。而在酸性介质中带正电的NH-fMWCNTs有助于在电极/电解质界面预富集带负电的分析物分子。GCE的修饰催化了橙黄II的氧化,氧化电位的负移和峰电流强度的增强证明了这一点。采用方波伏安法优化了各种实验条件,如支持电解质、电解质的pH值、沉积电位和沉积时间,以实现所设计传感器的最佳性能。在优化条件下,所设计传感器的检测限和定量限分别为0.57和1.92 nM。结果表明,二氧化钛作为光催化剂促进了橙黄II的催化降解研究。过氧化氢的加入进一步提高了染料的降解程度和速率。通过所设计的传感平台对橙黄II的分解进行了电化学探测,同时也通过紫外可见光谱进行了探测。染料按照准一级动力学降解高达92%。