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

It is urgent to develop highly active catalysts toward hydrogen peroxide (H 2 O 2 ) 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, Cu 2 O@Cu 9 S 5 yolk-shell nanospheres has been synthesized via a facial wet chemical method and applied as electrocatalyst for non-enzymatic H 2 O 2 sensor. These Cu 2 O@Cu 9 S 5 yolk-shell nanospheres with mean sizes of 230 nm consisting of Cu 2 O conductive core and Cu 9 S 5 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 H 2 O 2 of the Cu 2 O@Cu 9 S 5 yolk-shell nanospheres as a sensor has been obtained by comparing with those neat Cu 2 O nanospheres and Cu 9 S 5 hollow nanospheres. This noticeable property is largely due to the synergistic catalysis effect of the contribution of the Cu 2 O and Cu 9 S 5 . Cu 2 O@Cu 9 S 5 yolk-shell nanospheres based non-enzymatic H 2 O 2 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 H 2 O 2 , which is potentially superior to other similar Cu 2 O-based sensors that has been reported in the literatures. Additionally, this sensor also demonstrates excellent selectivity of H 2 O 2 in the presence of various coactive interferences. This novel Cu 2 O@Cu 9 S 5 yolk-shell nanospheres electrocatalyst provides a broad application prospect for H 2 O 2 sensing.