Morphology-dependent electrochemical activity of Cu2O polyhedrons and construction of sensor for simultaneous determination of phenolic compounds with graphene oxide as reinforcement

A series of Cu2O crystals with well-controlled cubic (C-Cu2O), star-shaped (S-Cu2O), and octahedral (O-Cu2O) structures were prepared by facile wet chemical method to explore the morphology-dependent electrocatalytic efficiency. When tested for the sensing of 4 - aminophenol (4-AP), 4 - chlorophenol (4-CP), and 4 - nitrophenol (4-NP), it was found that the O-Cu2O exhibited the best current signals, which were mainly because of its more exposed {111} facets and higher surface area. Further, O-Cu2O crystals were homogeneously dispersed on graphene oxide (GO) surface to achieve a hierarchical reinforcement structure. The electrode modified by O-Cu2O@GO showed high electrocatalytic activity toward the oxidation of 4-AP, 4-CP, and 4-NP, and could realize the selective detection of phenolic compounds in ternary electrolyte solutions and industrial wastewater. This work is beneficial to morphology tailoring and provides novel way to improve the electrochemical property of oxide-based catalysts as the promising applications in electrochemical sensors.