Tea waste-derived porous carbon: Electrochemical performance regulation and sensing applications

In this study, three porous carbon materials were prepared by using Xinyang maojian tea (MJ), black tea (BLT), and brick tea (BRT) waste. The tea waste-derived porous carbons (MJ-PC, BLT-PC, BRT-PC) exhibited different morphology and pore structure. Loose porous structures were obtained from BRT waste, maybe due to their original structure. Moreover, MJ-PC, BLT-PC, and BRT-PC showed varied electrochemical active surface areas (ECSAs), electron transfer abilities, electrocatalytic activity, and electrochemical oxidation capacity for p-aminophenol (4-AP) and acetaminophen (AC). As a result, the BRT-PC was selected as the sensitive material due to its outstanding performance, and a sensitive, reproducible, and selective electrochemical sensing platform for the simultaneous determination of 4-AP and AC was developed. Their detection limits are as low as 7 nM and 0.09 nM. Moreover, it has a high recovery in the detection of 4-AP and AC in paracetamol tablets and river water. This study provides a new way to tune the electrochemistry of porous carbon materials and to design new applications.