Eco-Friendly Heterogeneous Photocatalysis on Biochar-Based Materials Under Solar Irradiation

Abstract

Clean energy production and environmental remediation on carbon-based photocatalysts are shown in this work. Firstly, Au-supported on nanoporous biocharbased materials were prepared and used for hydrogen photoproduction under visible light irradiation. In presence of biochars, the photocatalytic activity increased by a factor up to 3 times higher than that obtained on a neat commercial semiconductor. In second place, the photocatalytic activity of S-and N-doped carbons was verified in the methylene blue photodegradation under artificial solar irradiation. Normalizing the kinetic results in terms of the weight of samples, the present results showed an increase in the photocatalytic activity up to 30 and 5 times higher on S-and N-doped biochars, respectively, than that obtained on a commercial semiconductor. The present results suggest that micropores in carbon materials play the role of microreactors and therefore harvesting solar energy for environmental remediation and clean energy production is possible by using free-semiconductor biochar-based materials.

Recent Progress in Biochar-Based Photocatalysts for Wastewater Treatment: Synthesis, Mechanisms, and Applications

“…In recent years, biochar-based photocatalysts (BCPs) have received great attention in various environmental fields [23][24][25][26][27]. Some of those recently reported BCPs were TiO 2 -coconut shell [28], TiO 2 -Salvinia molesta [29], TiO 2 -reed straw [30], TiO 2 -ramie char [31], TiO 2 -corn cob [32], TiO 2 -paper sludge and wheat husks [33], TiO 2 -bamboo [34,35], ZnO-waste biomass [36], g-C 3 N 4 /FeVO 4 -pinus roxbu rghii [37], Bi 2 O 3 -corn cobs [38], TiO 2 -walnut shells [39], TiO 2 -olive pits and TiO 2 -wood shaving [40], TiO 2 -wood pellets [41], and TiO 2 -plum stones [42], etc.…”

Dual Functionality of TiO2/Biochar Hybrid Materials: Photocatalytic Phenol Degradation in the Liquid Phase and Selective Oxidation of Methanol in the Gas Phase

“…phenolic hydroxyl, carbonyl and carboxyl groups) on the surface of biochar. [7][8][9][10] Worth mentioning is the work by Matos 10 on the preparation of biochar-based functional materials and investigation a wide spectrum of harmful compounds in water and air under visible light irradiation.…”

TiO2/Carbon Materials Derived from Hydrothermal Carbonization of Waste Biomass: A Highly Efficient, Low‐Cost Visible‐Light‐Driven Photocatalyst

“…The plot of ln(C 0 /C t )v ersus t shows al inear line and its equation gives the rate constant, k. The rate constant is an extremelye ffective parameter for comparisono ft he photocatalytic activity. [32] The use of rate constants makes it possible to do an independent comparison of the initial concentrationofo rganic contaminants. Figure 5A depicts the removal of MB based on its concentration changes.U nder visible-light illumination for 420 min, 3.1 % of MB was self-degraded.…”

“…The plot of ln( C 0 / C t ) versus t shows a linear line and its equation gives the rate constant, k . The rate constant is an extremely effective parameter for comparison of the photocatalytic activity . The use of rate constants makes it possible to do an independent comparison of the initial concentration of organic contaminants.…”