High catalytic performance non-enzymatic H2O2 sensor based on Cu2O@Cu9S5 yolk-shell nanospheres

Abstract

It is urgent to develop highly active catalysts toward hydrogen peroxide (H2O2) sensor in many industrial and biological processes, which usually is limited by high cost of instrumentation requirements and low-accuracy detection at low level. Herein, Cu2O@Cu9S5 yolk-shell nanospheres has been synthesized via a facial wet chemical method and applied as electrocatalyst for non-enzymatic H2O2 sensor. These Cu2O@Cu9S5 yolk-shell nanospheres with mean sizes of 230 nm consisting of Cu2O conductive core and Cu9S5 shell show numerous advantageous characteristics of well-sustained structural integrity, the homogeneous particle size distribution and visible mesoporosity morphology. The significantly improved electrocatalytic activity by catalyzing H2O2 of the Cu2O@Cu9S5 yolk-shell nanospheres as a sensor has been obtained by comparing with those neat Cu2O nanospheres and Cu9S5 hollow nanospheres. This noticeable property is largely due to the synergistic catalysis effect of the contribution of the Cu2O and Cu9S5. Cu2O@Cu9S5 yolk-shell nanospheres based non-enzymatic H2O2 sensor displays the relatively wide linear range from 0.1 μM to 3.5 mM with a high sensitivity of 299.74 μA mM−1 cm−2 but low detection limit of 28.83 nM (S/N ≥ 3) for electrochemical detection of H2O2, which is potentially superior to other similar Cu2O-based sensors that has been reported in the literatures. Additionally, this sensor also demonstrates excellent selectivity of H2O2 in the presence of various coactive interferences. This novel Cu2O@Cu9S5 yolk-shell nanospheres electrocatalyst provides a broad application prospect for H2O2 sensing.