Achieving Ni@(Pt/Ni(OH)2) ternary nanoflowers derived from Ni nanoflowers for electrochemical ammonia–nitrogen detection in the aqueous environment

Abstract

In this work, Ni nanoflowers were electrodeposited on the Ni foam surface. And then, ternary Ni@(Pt/Ni(OH)2) nanoflowers were fabricated on the surface of Ni nanoflowers based on the sample and facile galvanic replacement reaction between Ni nanoflowers and H2PtCl6·6H2O. The electrocatalytic activities of all synthetic Ni@(Pt/Ni(OH)2) toward ammonia oxidation reaction have been measured via cyclic voltammetry (CV). As the potential sensing electrode, the abilities of ammonia–nitrogen detection have been evaluated via CV and differential pulse voltammetry (DPV) under optimum conditions of prepared Ni@(Pt/Ni(OH)2) nanoflowers. The limit of detection is 0.82 μM with high sensitivity of 0.075 mA µM−1 cm−2. The measured results indicated that the fabricated sensor has good anti-interference ability, reproducibility and stability in ammonia–nitrogen determination. This obtained Ni@(Pt/Ni(OH)2) sensor exhibited good recovery in detecting ammonia–nitrogen in real samples including lake water from 97.59 % to 100.61 % and sea water from 93.86 % to 97.31 %, indicating a great potential application for the detection of ammonia–nitrogen in water.