Amorphous FeOOH quantum dots decorated on g-C3N4 nanosheets for high-performance energy storage electrodes

Quantum dots (QDs) have recently attracted intensive attention for electrode materials due to their tunable physical dimensions, unique surface effect and pseudocapacitive property. Nevertheless, direct employment of QDs as electrode materials are plagued because of their intrinsic aggregation. In this work, we have successfully fabricated amorphous FeOOH QDs and FeOOH/g-C3N4 hybrid nanosheets as electrode materials using a scalable and bottom-up synthesis route. The FeOOH/g-C3N4 composite possesses a unique heterostructure, comprising a highly dispersed FeOOH QDs anchored on g-C3N4 nanosheets. We probe the behavior of as-prepared hybrid sample, which collectively delivers significant improvement in terms of ultrahigh specific capacitance and long-term stability. The FeOOH/g-C3N4-20 electrode exhibits a large specific capacitance of about 270.8 F g(-1) at 1 A g (-1), prominent rate capability at high scan rates, and favorable capacitance retention (78.3% capacitance retention after 3000 cycles).