Lignin containing cellulose nanofiber/AgSe nanocomposite films: a promising material for thermoelectric film generators.

This work deals with the fabrication of lignin containing cellulose nanofiber (LCNF)/AgSe films for thermoelectric applications. AgSe nanoparticles were synthesized within the LCNF network through methods, employing NaSeO and AgNO along with microwave energy treatment. LCNF/AgSe films fabricated with two LCNF : AgSe weight percent ratios (, 50 : 50 and 30 : 70) were used to construct a flexible thermoelectric module. The obtained AgSe nanoparticles displayed a uniform size distribution in the LCNF network with smaller dimensions from the microwave energy treated group. The microstructure of LCNF/AgSe films was improved by hot-pressing, leading to enhanced film density thermoelectric properties. At a differential temperature of 50 K, films with 50% and 70% of AgSe exhibited output voltages of 18 and 21 mV; and Seebeck coefficients of -60 and -70 μV K at 350 K, respectively. When microwave energy was applied, the films at 50% and 70% AgSe showed highest output voltages of 19 and 33 mV, respectively, and Seebeck coefficients of -63.3 and -110 μV K at 350 K. The low-cost fabrication process associated with this module opens a pathway for applications such as energy harvesting.