Photoinduced Zn‐Air Battery‐Assisted Self‐Powered Sensor Utilizing Cobalt and Sulfur Co‐Doped Carbon Nitride for Portable Detection Device

Abstract

Abstract Most self‐powered electrochemical sensors (SPESs) are limited by low open circuit voltage and power density, leading to a narrow detection range and low sensitivity. Herein, a photoinduced Zn‐air battery‐assisted SPES (ZAB‐SPES) is proposed based on cobalt and sulfur co‐doped carbon nitride with the cyano group (Co, S‐CN). The cyano functionalization remarkably enhances visible light utilization, and the cyano moiety acts as an electron‐withdrawing group to promote electron enrichment. Co and S co‐doping can create a p–n homojunction within carbon nitride, enabling the efficient migration and separation of carriers, thereby significantly improving the performance of the oxygen reduction reaction. The synergistic effects endow Co, S‐CN photocathode with an open circuit voltage of 1.85 V and the maximum power density of 43.5 µW cm−2 in the photoinduced ZAB. Employing heavy metal copper ions as the target model, the photoinduced ZAB‐SPES exhibited dual‐mode and sensitive detection. Furthermore, a portable detection device based on the photoinduced ZAB‐SPES is designed and exhibits high linearity in the range of 5 ~ 600 nM with a detection limit of 1.7 nM. This work offers a portable detection method based on the photoinduced ZAB‐SPES in the aquatic environment.

Keywords

• carbon nitride
• device
• portability
• self‐powered sensor
• Zn‐air battery