With the swift evolution of smart products, flexible electronics characterized by their light weight, high flexibility and superior extensibility are becoming more and more fashionable in our daily life. As the foundational elements of flexible electronics, flexible electrodes have made a big splash in recent years in diverse fields of brain–computer interfaces, touch-screen displays, intelligent robots, and wearable and implantable devices. In this context, we analyzed the development of flexible electrode materials for electronics in the last 10 years by literature visualization. Our central emphasis is on all aspects of flexible electrodes, with a primary focus on flexible substrates (hydrogel/aerogel, fiber/fabric, polymer films) and active materials (metal and derivatives, carbon-based materials, MXenes, MOFs, etc.). Further, we extensively discuss the manufacturing methods of flexible electrodes, involving printing, vacuum filtration, deposition, electro/chemical plating, and others. The flexible electrodes have the potential to address a wide range of applications in flexible sensors, energy storage, and healthcare. Overall, the major challenges and future aspects of flexible electrodes are discussed for fabricating a new generation of flexible electronics.

Traditional triethylamine (TEA) sensors suffer from the drawback of serious cross-sensitivity due to the low charge-transfer ability of gas-sensing materials. Herein, an advanced anti-interference TEA sensor is designed by utilizing interfacial energy barriers of hierarchical Bi₂O₃/WO₃ composite. Benefiting from abundant slit-like pores, desirable defect features, and amplification effect of heterojunctions, the sensor based on Bi₂O₃/WO₃ composite with 40% Bi₂O₃ (0.4-Bi₂O₃/WO₃) demonstrates remarkable performance in terms of faster response/recovery time (1.7-fold/1.2-fold), higher response (2.1-fold), and lower power consumption (30 °C-decrement) as compared with the pristine WO₃ sensor. Furthermore, the composite sensor exhibits long-term stability, reproducibility, and negligible response towards interfering molecules, indicating the promising potential of Bi₂O₃/WO₃ heterojunctions in anti-interference detection of low-concentration TEA in real applications. This work not only offers a rational solution to design advanced gas sensors by tuning the interfacial energy barriers of heterojunctions, but also provides a fundamental understanding of hierarchical Bi₂O₃ structures in the gas-sensing field.