Electrochemical environmental pollutant detection enabled by waste tangerine peel-derived biochar

Nitrite is widely utilized in food and agricultural fields. Excessive nitrite causes great harm to ecosystems and human health, rendering it one of environmental pollutants. In this work, tangerine peel, as a common agricultural waste in daily life, is considered as a sustainable, renewable and low-cost carbon precursor. Tangerine peel waste has been re-utilized to prepare biochar of iron oxide/nitrogen-doped carbon nanocomposite in constructing electrochemical sensor for nitrite determination. Two electrochemical techniques of linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were practiced for quantifying nitrite. The biochar of iron oxide/nitrogen-doped carbon nanocomposite displayed satisfactory sensing performance in different real environmental samples of soil, spinach and mustard. Agricultural waste to value-added product is becoming increasingly significant. Considering that a lot of tangerine peel is discarded as waste in daily life, the present strategy will be promising to transform a common agricultural waste into value-added product, thus having profound significance in contributing to both the smart farming, pollution alleviation and environmental pollutant monitoring. [Display omitted] •Large amount of tangerine peel waste is indiscriminately discarded every year.•Tangerine peel waste has been converted into functional biochar.•Tangerine peel waste is a sustainable, renewable and low-cost material.•Electrochemical sensor for detecting nitrite was constructed using biochar.•Tangerine peel waste to value-added product has been realized.