Content Of Oxygen Functional Groups Research Articles

The spatiotemporal heterogeneity of fertosphere hotspots impacted by biochar addition and the implications for NH3 and N2O emissions

The fertosphere, as the interfaces between fertilizer granular and soil particles, represents a key hotspot for nitrogen transformation processes, particularly for ammonia (NH3) and nitrous oxide (N2O) emissions. Understanding the heterogeneity of the fertosphere, especially when incorporating organic amendments like biochars, is crucial for predicting NH3 and N2O emissions after soil fertilization. In this study, we investigated the effects of three types of biochar (pristine, aged, and acid-washed biochar) on heterogeneity of fertosphere induced by localized urea application. pH-specific planar optodes were employed to visualize pH gradients in fertosphere hotspots with high spatial and temporal resolution. In addition, we conducted thorough measurements of the gradient distribution of electric conductivity (EC), mineral N, aqueous NH3 in soil and enzyme activities relevant to nitrification. Concurrently, NH3 and N2O emissions from the soil were continuously monitored at a high temporal resolution. Initially, urea-induced fertosphere exhibited significant NH3 emissions, primarily attributed to the pH elevation resulting from urea hydrolysis. However, after 6 days, NH3 emissions subsided, and there was a notable sharp increase in N2O emissions. Importantly, compared to urea application alone, the inclusion of pristine biochar led to a delay in soil pH decline with a 19% rise in NH3 emission. Aged biochar, characterized by a higher content of oxygen functional groups, demonstrated increased NH4+/NH3 adsorption capacity and enhanced ammonia monooxygenase (AMO) activity in soil, resulting in an 18% reduction in NH3 emission. While a slight decrease of 5% in NH3 cumulative emission was observed in the acid-washed biochar treatment. Notably, biochar could potentially promote nitrification-derived N2O emissions due to the accumulation of NH3 oxidation products (NH2OH). These findings could contribute to refining N transformation models for fertilized soils, and optimizing N fertilizer application strategies.

Upgrading waste tire to a carbon-based natural gas diffusion electrode for efficient H2O2 production

Carbonaceous material, especially carbon black, is crucial in H2O2 production due to its exceptional catalytic properties. However, the traditional carbon black production process faces the challenges of significant CO2 emissions and high costs. To overcome these challenges, porous carbon nanoparticles (TPCNs) are derived from cheap, sustainable waste tires by a facile pyrolysis process, which is then used to fabricate a natural gas diffusion electrode (GDE) for efficient H2O2 electrogeneration. The obtained TPCNs are amorphous carbon with high graphitization, hierarchically porous architecture, and have high oxygen functional group content of CO, C-O-C, and COOH that are favorable for the high H2O2 selectivity. Hence, the fabricated TGDE exhibits efficient H2O2 electrogeneration of 694 mmol L–1 H2O2 concentration with 62% current efficiency after 60 min electrolysis without aeration. Moreover, this H2O2 production process utilizing waste tire can decrease by 19.6% CO2 emissions compared with that using commercial carbon black. This work proposes a protocol for the high-value reuse of waste tires and provides a sustainable carbon-based catalyst production for efficient H2O2 electrogeneration.

High Performance Metal Oxide–Reduced Graphene Oxide Electrocatalyst for All Vanadium Redox Flow Batteries

Vanadium redox flow battery (VRFB) is one of the most favorable technologies for large-scale energy storage applications owing to its numerous gorgeous features, such as flexible design, high safety, and long cycle life. In this study, metal oxide (MOx)–reduced graphene oxide (rGO) nanohybrid was successfully synthesized via a facile hydrothermal route followed by annealing and employed as an electrocatalyst to modify the graphite felt (GF) electrode material for all-vanadium redox flow batteries (VRFBs) application. The as-synthesized MOx–rGO nanohybrid reveals good electrocatalytic reversibility and higher anodic and cathodic peak current density for V3+/V2+ and VO2 +/VO2+ redox couples compared with those of rGO and MOx samples. The voltage efficiency of the VRFB using MOx–rGO nanohybrid reaches 84% at 80 mA cm−2, which is 4% and 13% higher than the VRFBs using the rGO-loaded GF electrode and the pristine GF electrode, respectively. It still shows the voltage efficiencies of 76% and 70% at relatively high current densities of 120 mA cm−2 and 140 mA cm−2, respectively, but other samples have no effective discharge. This improvement is accredited to the uniform distribution of MOx nanoparticles on the rGO surfaces, avoiding the restacking of the rGO sheets and conquering nanoparticles aggregation, which might boost the effective active surface area and improve mass transport at the electrode-electrolyte interfaces. Besides, the existence of oxygen vacancies on MOx, the high electrical conductivity of rGO, and the high content of oxygen functional groups play the prodigious roles to facilitate the reversibility of vanadium ions redox reactions.

Ultrasonic–Thermal Regeneration of Spent Powdered Activated Carbon

This study investigated the ultrasonic–thermal regeneration of powdered activated carbon (PAC) spent using 4-chlorophenol (4-CP). Similarly, a thermal regeneration process was also studied and the reaction conditions (i.e., regeneration temperature, heating rate, regeneration time) were tested. Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis were applied to characterize the regenerated PACs under different treatments (thermal, ultrasonic and ultrasonic–thermal) and also compare them with the fresh and exhausted PACs. According to our regeneration observations, the ideal regeneration parameters were determined to be a 40 kHz frequency, 0.18 W/mL sonication power, 0.1 M NaOH and 50% (v/v) ethyl alcohol as the regeneration solution, and 1 g/L of saturated PAC mass with thermal regeneration as the second stage at 500 °C, desorbed for 30 min with a heating rate of 20 °C min−1. Under these conditions, the RE value achieved 90.99% and the η value reached 5.6%. The results of FTIR, XPS and XRD revealed that the oxygen functional group content of ultrasonic–thermal regenerated PAC significantly increased. These oxygenous groups exerted a positive effect on the adsorption process of the regenerated PAC and the subsequent adsorption–regeneration process.

A hydrophobic and hierarchical porous resin-based activated carbon modified by g-C3N4 for toluene capture from humid conditions

The synthesis of hydrophobic and hierarchical porous activated carbon (AC) used for toluene capture from a humid atmosphere still remains a challenge. In this work, a novel hydrophobic and hierarchical porous AC was prepared from resorcinol-formaldehyde resin spheres using g-C3N4 as a new pore-forming agent. By the proper participation of g-C3N4, the obtained adsorbent GNHRC-1.5 was endowed with an excellent toluene adsorption capacity (10 mmol/g) under low pressure of P = 0.2 kPa, which was 54% higher than that of nonmodified resin-based AC. By DIH (Difference of Isosteric Heats) prediction, the adsorption selectivity of GNHRC-1.5 to toluene/water was further enhanced to 139.55, higher than that of other reported adsorbents. Toluene breakthrough tests and kinetic analysis showed that GNHRC-1.5 possessed a faster intraparticle diffusion and outstanding reusability, which was ascribed to its a certain amount of mesopores. Grand Canonical Monte Carlo and molecular dynamics simulation were applied to explore the competitive adsorption mechanism of toluene and water vapor from the perspective of pore size and surface functional groups. The results indicated that the competitive adsorption was controlled by Van der Waals energy, intramolecular energy and electrostatic energy. Both the higher content of narrow micropores below 1 nm and carboxyl are not beneficial for toluene adsorption under humid conditions. For GNHRC-1.5, an appropriate micropore distribution, a certain amount of mesopores, and a lower content of oxygen functional groups, afford it excellent adsorption selectivity for toluene and fast adsorption kinetics under humid conditions.

Investigation on the structure evolution and thermochemical conversion characteristics of lignite after different pretreatment

Despite the importance of hydrothermal treatment dewatering (HTD) as a means of utilizing lignite efficiently and cleanly, there have been relatively few studies on its downstream combustion and gasification characteristics. Particularly, what kind of thermochemical process is more favourable, which has not been investigated. At the same time, conventional flue gas treatment (FTD) is a relatively mature lignite pretreatment technology and is selected for comparative analysis. The present study examined the thermochemical characteristics and physicochemical structure of upgraded lignite by HTD and FTD processes. A combined process with great practical application foreground is proposed. Results showed that both HTD and FTD processes can profit dehydration and deoxidation of lignite. HTD process has a better effect in terms of dehydration because of the high amount of O-containing functional group removal. In terms of aromaticity and coal-rank, upgraded lignite treated with HTD is inferior to that treated with FTD. The comprehensive combustion characteristics indexes of upgraded lignite are increased by HTD and decreased by FTD, indicating that the HTD process promotes the combustion reactivity of upgraded lignite. HTD and FTD processes both decrease the gasification reactivity of upgraded lignite. Compared with the HTD, the FTD process is more likely to reduce the gasification rate. Compared with effective coal rank and the concentration of oxygen functional groups, the revived microstructure of upgraded lignite has a greater impact on combustion and gasification reactivity. The HTD process was more prone to the breakdown of chemical groups rather than crosslinking. These findings are consistent with the results of kinetic analysis. In general, compared with FTD, upgraded lignite by HTD process is in favor of downstream thermochemical application. The comparison of different thermochemical characteristics, including combustion, gasification, pyrolysis, are analyzed. The effective application with combined process of HTD and pyrolysis and waste water coke slurry have industrial application prosperity.

The mechanism and sorption kinetic analysis of hydrogen storage at room temperature using acid functionalized carbon nanotubes

The present work investigates the effect of acid functionalization of multiwalled carbon nanotubes (MWCNTs) on the physisorption based mechanism of hydrogen storage at room temperature. For this purpose, a suite of functionalized CNT samples is synthesized and subjected to a comprehensive range of material characterization techniques and hydrogen storage measurements. Nitric acid (HNO3) and the mixture of sulphuric acid and nitric acid (H2SO4:HNO3) are used for the synthesis at oxidation temperatures of 80 °C and 100 °C. Electron microscopy and X-ray photoelectron spectroscopy results reveal that acid functionalization causes major alternation in the physicochemical properties of the CNTs due to the varied concentration of oxygen functional groups. Particularly, the H2SO4:HNO3 functionalized sample at 100 °C is found to have the highest interlayer spacing, oxygen to carbon ratio (26.09 at. %), defect content, and specific surface area (215.3 m2/g). These features collectively contribute to substantially improved hydrogen storage properties, including a ∼150% increase in the hydrogen storage capacity at 298 K and 50 bar. Furthermore, kinetic analysis shows that the desorption follows a multiple diffusion process which is sensitive to the oxygen functional groups and structural defects, hence reducing the rate of desorption; whereas the adsorption is controlled by a more rapid, three-dimensional diffusion process.

Facile synthesis of carbon nanotubes and cellulose nanofiber incorporated graphene aerogels for selective organic dye adsorption

We introduced a facile and economical method to fabricate graphene aerogels (GAs) with controllable structural properties by incorporating carbon nanotubes (CNTs) and carbon nanofibers (CNFs), and its application in organic dye adsorption is demonstrated. The GAs combined with CNTs and CNFs were synthesized by the hydrothermal method. The adsorption capacity of these CNT-CNF-GA (CCGA) towards cationic dyes (rhodamine 6G (R6G) and methylene blue (MB)) and anionic dyes (methyl orange (MO)) was examined. The presence of oxygen functionalities gives an overall negative charge to CCGA, which exhibited a high adsorption capacity for cationic MB and R6G (96.1 mg/g and 79.2 mg/g, respectively) dyes and a relatively low adsorption capacity towards MO (51.6 mg/g). Further, by adjusting the hydrothermal treatment time, the oxygen functional group content and the surface area of CCGA were optimized to improve the adsorption capacity. All these imply that the porosity of GA, chemical and physical interaction of functional groups, overall charge on GA and the dye molecules, and the size of the dye molecules are the main criteria that affect the selective dye adsorption. These CCGAs exhibited a better adsorption capacity as well as good reusability, indicating their potential for practical use as a dye adsorbent.

High energy supercapacitors based on functionalized carbon nanotubes: Effect of atomic oxygen doping via various radiation sources

Herein, carbon nanotubes (CNTs) were oxygen functionalized by irradiation with diverse radiation sources including Am-241, Sr-90, Co-60, and Na-22 for the first time to be used as the electrode material in a high-energy supercapacitor. The oxygen contents of the irradiated CNTs were fine-tuned via the energy of the radiation source. The physicochemical characterization of as-obtained CNTs was conducted by X-Ray Diffraction (XRD), Raman, and Scanning Electron Microscopy, Energy Dispersive X-Ray (SEM- EDX) analysis whereas cyclic voltammetry and galvanostatic charge-discharge techniques were performed to assess the electrochemical performance of the as-assembled symmetrical supercapacitor cells. The CNT irradiated by Am-241 radiation source offered superior specific capacitance values compared to the other irradiated CNTs thanks to its higher content of oxygen functional groups. The highest specific capacitance for CNT Am-241 sample (with 7.32% oxygen) was calculated to be 489.6 F.g−1 at a current density of 0.1 A.g−1, which was almost 2.75 fold that of non-irradiated CNT sample. The capacitance retention of as-synthesized CNT Am-241 was determined as 98.50% for the 5,000th CV cycle. The outstanding energy density of 56.90 W.h.kg−1 was achieved even at a high power density value of 9992.19 W.kg−1, comparable to the commercial batteries, will pave the way for facile fabrication of high-energy electrochemical energy storage systems based on functionalized carbon nanotubes.

Converting spent carbon cathode (SCC) into SCC-2600@rGO for superior Li+ storage performance

Exploiting the characteristics of carbonaceous solid waste for added-value applications is a potential strategy for realizing resource recycling and reducing pollution. Graphitized spent carbon cathode (SCC) used as negative electrodes in lithium-ion batteries exhibits unacceptable high-rate cycle performance. In this study, the effect of the heating rate on the microstructure and electrochemical properties of SCC-2600@rGO fabricated by the self-cycling combined with interfacial assembly was investigated. SCC-2600@rGO-8 has the abundant defects, appropriate content of oxygen functional groups, hierarchical pore structure, and complex graphene conductive network. And the unique microstructures can provide numerous active sites for lithium storage, accelerate the charge transfer rate, and maintain structural stability. As a consequence of these features, SCC-2600@rGO-8 anodes have the attractive electrochemical properties, including a high charge capacity (753.1 mAh/g at 0.1 C after 50 cycles) and a notable rate capability (614.9 mAh/g at 1 C after 500 cycles and 278.0 mAh/g at 5 C after 2500 cycles).

A study of the correlation between the oxidation degree and thickness of graphene oxides

Thickness control is very important to commercial applications of 2D nanomaterials. The thickness of graphene oxide (GO) layers varies depending on the fabrication process, which is directly influenced by the content of oxygen functional groups. The correlation between the thickness and the degree of oxidation in different types of GO samples fabricated by various process are investigated through macroscopic and microscopic analysis. In this experiment, fabricated differently four GOs having various degree of oxidation were analyzed by X-ray Photoelectron Spectroscopy (XPS) to evaluate the degree of oxidation, respectively. A monolayer analysis by Atomic Force Microscope (AFM) and d-spacing analysis by X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) were employed to compare and analyze the effect of the degree of oxidation on the thickness of the GO layers. The results showed that the degree of oxidation had a directly proportional relationship with the thickness and d-spacing of the specimens. Raman spectroscopy was also employed to further verify the proportional relationship between the degree of oxidation and the thickness of the GO specimens. The degree of oxidation of GO is to approximate by the analysis using the Raman spectroscopy, XRD and TEM results.

Improving the Electrochemical Performances of Supercapacitors through Modification of the Particle Size Distribution of the Carbon Electrode

The effect of a synergetic mixture of large and small activated carbon composite particles on the performance of organic electrolyte-based EDLCs was examined in this work. Different surface areas, pore volumes, particle size distributions, and concentrations of surface functional groups were observed in bi-modal particle sizes of activated carbon composites. Using galvanostatic cycling, the cell capacitance of an activated carbon composite rose with an increase in the fraction of big particles (C8) over a wide range of rates. Due to their moderate specific surface areas, a relatively low fraction of smaller particle size, low concentration of oxygen functional groups, low contact resistance, and high ionic conductivity, the 0.25C4+0.75C8 carbon electrode composite has a high specific capacitance, high retention of high rate discharge, and long cycle life when compared to other composites and single carbon electrodes (C4, C8, and C12). The leakage current and gas evolution may be suppressed to an operating voltage of 3.0 V with an appropriate fraction of large and small particle composition on the carbon electrode, boosting the carbon cells’ reliability and stability.

Adsorption behavior and mechanism of Cd (II) by modified coal-based humin

Shanxi coal-based humin (SCH) was extracted using sequential alkali extraction from Shanxi Lingshi coal, and obtained the modified coal-based humin (Ca-SCH) by Ca(OH) 2 . On the basis of the problem of SCH’s high alkalinity and low adsorption amount to heavy metals, SCH was modified by using Ca(OH) 2 and characterized by a series of representation analysis, and studied by static adsorption experiments for the adsorption kinetic and thermodynamic characteristics of SCH and Ca-SCH to Cd (II). Results showed that scanning electron microscope (SEM), BET method and X-ray photoelectron spectroscopy (XPS) certificated that the Ca (II) was loaded onto Ca-SCH successfully. In addition, the surface of Ca-SCH became coarse, the pore diameter of Ca-SCH increased, and content of oxygen functional groups also increased which was beneficial to the adsorption of Cd (II). The adsorption equilibriums of SCH and Ca-SCH were reached within 120 min, which accord with the pseudo-second-order kinetic equation, and the adsorption isotherms were well depicted by the Langmuir and Freundlich models. The maximum adsorption capacity (Qm) of Cd (II) on Ca-SCH was 89.29 mg ⋅ g −1 , and increased 23.23% compared with SCH. By chemical modification, the Ca (II) can be boned to Ca-SCH, and Ca (II) and Cd (II) by ion exchange can be used to improve the adsorption performance of SCH, which is valuable for deactivating of Cd (II) in soil. • Coal-based humin was extracted using sequential alkali extraction. • Modified coal-based humin was prepared through Ca(OH) 2 . • A significant improvement in activity and pore diameter of modified coal-based humin. • Modified coal-based humin showed more adsorption capacity for Cd(II) than coal-based humin. • Adsorption mechanisms were cation exchange, chemical adsorption, and physical adsorption.

MoO2–graphene nanocomposite as an electrocatalyst for high-performance vanadium redox flow battery

MoO2–reduced graphene oxide composite (MoO2–rGO) acts as the electrode material for all-vanadium redox flow battery (VRFB). MoO2–rGO composite exhibits excellent electrocatalytic redox reversibility for V3+/V2+ and VO2+/VO2+ and larger anodic and cathodic peak currents than those of other individual MoO2 and rGO samples. The voltage efficiency of the VRFB using MoO2–rGO nanocomposite at 80 mA cm−2 is 82.14%, which is 4.23% and 13.56% higher than the VRFBs using the rGO-coated graphite felt electrode and the graphite felt electrode, respectively. It still shows the voltage efficiencies of 73.83% and 68.50% at 120 mA cm−2 and 140 mA cm−2, respectively, but other samples have no effective discharge. This improvement is attributed to the uniform distribution of MoO2 nanoparticles on the rGO surface, avoiding the restacking of the rGO sheets and suppressing nanoparticle aggregation, which might increase the effective surface area and improve mass transport at the electrode-electrolyte interface. Furthermore, oxygen vacancies on MoO2, the high electrical conductivity of rGO, and the high content of oxygen functional groups act as active sites for the vanadium ion redox reaction.

Relationship between Cytotoxicity and Surface Oxidation of Artificial Black Carbon.

The lacking of laboratory black carbon (BC) samples have long challenged the corresponding toxicological research; furthermore, the toxicity tests of engineered carbon nanoparticles were unable to reflect atmospheric BC. As a simplified approach, we have synthesized artificial BC (aBC) for the purpose of representing atmospheric BC. Surface chemical properties of aBC were controlled by thermal treatment, without transforming its physical characteristics; thus, we were able to examine the toxicological effects on A549 human lung cells arising from aBC with varying oxidation surface properties. X-ray photoelectron spectroscopy, as well as Raman and Fourier transform infrared spectroscopy, verified the presence of increased amounts of oxygenated functional groups on the surface of thermally-treated aBC, indicating aBC oxidization at elevated temperatures; aBC with increased oxygen functional group content displayed increased toxicity to A549 cells, specifically by decreasing cell viability to 45% and elevating reactive oxygen species levels up to 294% for samples treated at 800 °C.

Simultaneous effect of fluorine impregnation on highly mesoporous activated carbon used in high-performance electrical double layer capacitors

Owing to the increase in need for high-performance energy storage devices, activated carbon has attracted considerable attention as an electrode material for electrical double-layer capacitors (EDLCs). However, the conventional manufacturing process of activated carbon is seriously limited by the depletion of raw material sources. Biomass-based activated carbon, which is currently considered as a breakthrough, exhibits performance limitations such as low specific capacitance and poor high-rate performance. In this study, we propose the use of fluorine-doped mesoporous carbon (F-MAC), which is derived from Ecklonia cava using fluorine impregnation and KOH activation, to address the above challenges. F-MAC exhibits high specific capacitance (184 F/g), excellent high-rate performance (155 F/g at a current density of 20 A/g), and superior cycle stability (82.8% capacitance retention after 2,000 cycles). These performance improvements are attributed to the increased surface area, high mesopore volume fraction, fluorine-doping effect, and high concentration of oxygen functional groups.

A study of plasma power effects on surface activation of polystyrene

In this study, polystyrene (PS) surface activation was performed with cyclonic atmospheric-pressure plasma to improve surface hydrophilicity, and the effects of plasma power on cyclonic plasma surface activation were investigated. Altered PS surface characteristics were observed through a wettability analysis. The PS surface hydrophilicity was highly enhanced during the cyclonic plasma treatment. The substantial growth of the PS surface hydrophilicity was attributed to the crosslinking by activated species of inert gases due to the presence of cyclonic plasma. Optical emission spectroscopy was used to determine various chemical plasma species and the association of the plasma surface treatment with the changes in the electron density and electron excitation temperature in cyclonic plasma with increasing plasma power. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy were used to determine the chemical and morphological variations on the cyclonic plasma-treated PS surface. The XPS analysis exhibited noticeably higher surface concentrations of oxygen functional groups on the cyclonic plasma-activated PS surface compared to the untreated PS. The results show that cyclonic plasma is an operative plasma device that can be used to improve PS surface hydrophilicity.

Functional groups evolution during GBW110031 anthracite combustion based on molecular models construction

Fourier transform infrared spectroscopy (FTIR) and Carbon-13 nuclear magnetic resonance (13C NMR) techniques were applied to establish the molecular models of anthracite combusted at 490 °C and 690 °C (490-C and 690-C). The evolution laws of functional groups were investigated based on the constructed models and quantitative changes calculated by FTIR results. The content of aromatic groups kept decreasing before 500 °C; –CH3/–CH2– showed a rising trend during combustion; and the content of oxygen functional groups kept declining before 400 °C. The chemical formulas of 490-C and 690-C were C217H106O12N2S2 and C201H59O8N3S2, respectively. 690-C model was more compact than that of original anthracite and 490-C due to the spilt of carbon skeleton and the shedding of aliphatic chains during combustion. Total sulfur content in anthracite showed a sudden rise at 690 °C which could be attributed to the generation of organic thiophene; one more pyrrole in 690-C model resulted from the conversion of pyridine at such high temperature.

The Effects of Oxygen Functional Groups on Graphene Oxide on the Efficient Adsorption of Radioactive Iodine.

Oxygen-containing functional groups tend to induce a strong interaction between solid adsorbents and iodine molecules, yet have not been systematically investigated. Herein, on the basis of a series of nitric acid-treated graphene oxide (GO) with different contents of oxygen functional groups for iodine adsorption, it was found that the iodine uptake capacity is proportionate to the oxygen content and the diversities of oxygen-containing groups. The density functional theory (DFT) calculation results also suggest that oxygen-containing groups result in strong interactions between iodine molecules and the adsorbents through a covalent bond-forming process, among which -OH groups possess a higher adsorption energy averagely. Such theoretical and experimental work deepens our understanding of the effects of oxygen functional groups on iodine adsorption and provides novel ideas for future design and synthesis of high-performance solid adsorbents for radioactive iodine.

Efficient removal of volatile organic compound by ball-milled biochars from different preparing conditions

Adsorption is an important technology to deal with volatile organic compounds (VOCs), and biochar has attracted much attention as a new type of adsorbent for VOCs. In this study, rice husk, corn stover and pine wood sawdust biochars from different pyrolysis temperatures (300 °C, 500 °C and 700 °C) were synthesized and treated by ball milling. The pristine and ball-milled biochars were used as adsorbents for acetone and toluene removal. Results showed that wood biochar had higher adsorption capacity for VOCs. After ball milling, the BET specific surface area and the oxygen functional group content of biochars increased. With these changes, all the ball-milled biochars showed higher adsorption rate than the pristine biochars. The ball-milled biochars under pyrolysis temperature of 300 °C showed the best adsorption performance for acetone (304 mg g−1), which was 1.7-fold greater than that of pristine biochar. Increasing the surface area by ball milling is conducive to the diffusion of hydrophobic VOCs molecules such as toluene to the adsorption sites in the biochar. However, for hydrophilic VOCs such as acetone, higher oxygen functional groups were the main reason for the enhanced adsorption by ball milling. Therefore, ball-milled biochar can be used as a potential adsorbent material in VOCs treatment.