Sensors have become integral part of our lives. Electrochemical sensors are the oldest and the most commercially used sensors. Biomass carbonization by pyrolysis and hydrothermal methods are discussed as a cost-effective strategy for fabrication of electrodes for electrochemical sensing applications. Porosity and surface area along with graphitic nature of bio derived carbon materials greatly affects the performance of electrochemical sensors. Various techniques are used to improve the surface properties so as to enhance the electrocatalytic behavior of working electrodes. Synthetic and bioderived carbon materials are compared for their electrochemical sensing applications.

Surface properties always play a dominant role in the energy storage devices. Understanding the surface phenomena is the key to tune the energy storage device using biowaste based porous nano carbons. Here, Callerya atropurpurea pod derived peculiar porous nanocarbons are synthesized by pyrolysis at different temperatures without any synthetic templates approach. Elaborate analysis of surface textures on the effect of pore size, volume and specific surface area on specific capacitance and frequency response behavior of nanocarbons were studied in detail. Electrochemical characterizations establish the mutuality of porosity and microtextural properties of nanocarbons with specific capacitance. The electrochemical characterization of the novel materials as supercapacitor electrode shows a high specific capacitance of 326.54 F g⁻¹ at 0.25 A g⁻¹ in 1.0 M KOH. A practical symmetric supercapacitor device is fabricated with a specific capacitance of 86.38 F g⁻¹ at 0.1 A g⁻¹, and high energy density of 27.0 Wh kg⁻¹. This symmetric supercapacitor also possesses outstanding capacitance retention of 92.16% for 5000 charge discharge cycles and also stability of 97.17%, after voltage holding at the maximum voltage for 100 hours. Present manuscript gives the strong evidence for structure‐property relationships so that one can tune the energy storage devices effectively.