Water-Phase Exfoliated Biochar Nanofibers from Eucalyptus Scraps for Electrode Modification and Conductive Film Fabrication

Abstract

A solvent-free strategy to produce water-dispersed biochar-nanofibers (BH-CNF) is reported, demonstrating the potential of this cost-effective and sustainable material in electrochemical sensing and fabrication of conductive films. Water-phase BH-CNF from eucalyptus scraps were achieved using a Kraft process followed by liquid-phase exfoliation assisted by the biological stabilizing agent sodium cholate. BH-CNF-based sensors were constructed following two strategies: surface modification of screen-printed electrodes and fabrication of exclusively nanofiber-based flexible sensors. The latter were fabricated through a procedure that is cost-effective and within everyone’s reach. The potentiality of the BH-CNF-based sensors has been challenged toward a wide range of analytes containing phenol moieties and applied for detection of o-diphenols and m-phenols in olive oil samples. The BH-CNF-based sensors exhibited repeatable (RSD ≤ 7%, n = 5) and reproducible (RSD ≤ 10%; n = 3) results, proving their applicability in electroanalytical applications and the robustness of the exfoliation and fabrication strategy. For sample analysis, LODs for hydroxytyrosol (LOD ≤ 0.6 μM) and tyrosol (LOD ≤ 3.8 μM), intersensor precision (RSD calibration slope < 7%, n = 3), and recoveries obtained in real sample analysis (91–111%, RSD ≤ 6%; n = 3) endorse the material exploitability in real analytical applications.

Removal Efficiency and Performance Optimization of Organic Pollutants in Wastewater Using New Biochar Composites

“…Moreover, slow pyrolysis is the commonly used preparation method of BC. Additionally, preparation conditions are also an important factor affecting the preparation process of BC [20]. Figure 10 displays the main preparation process of BC.…”

Recent Advances of Biochar-Based Electrochemical Sensors and Biosensors

“…The effect of biochar’s morphology might be one of the key factors for the enhancement of the catalytic ability of biochar. For example, Bukhari et al, prepared a type of water-dispersed biochar, with a nanofiber structure, from pyrolysis of eucalyptus scraps [ 32 ]. The prepared biochar-nanofibers (BH-CNF) exhibited good electrochemical catalytic capacities for phenolic compounds.…”

“…Since biochar is catalytic, it can be directly used to make electrodes, such as screen-printed electrodes and carbon-paste electrodes. As stated above, Bukhari et al, used the prepared BH-CNF to directly fabricate an electrochemical sensor [ 32 ]. As graphically shown in Figure 2 , a BH-CNF-based sensor was constructed following five steps: BH-film preparation, electrode-base preparation, BH-film and electrode-base alignment, BH-film transfer by thermal lamination, and an assembled BH-film-equipped electrode.…”

Modified Water Hyacinth Biochar as a Low-Cost Supercapacitor Electrode for Electricity Generation From Pharmaceutical Wastewater

“…Jiang et al showed that macroporous wood biochar has a high potential for ion movement than microporous wood biochar that can enhance electricity generation [4]. Various biomass substrates have been used for biochar production such as peanut shell [5], tea saponin [6], eucalyptus scraps [7], cotton rose [8], sugarcane bagasse [9], and others.…”