Aromatic Structures Research Articles

Co-evolution with pore and molecular structure during tar-rich coal pyrolysis

In-situ pyrolysis of tar-rich coal is a potentially green and low-carbon development technology. However, there are restrictions on the transport of tar and gas products due to the evolution of pore structure during pyrolysis. Hence, revealing the evolution of pore structure during pyrolysis is helpful to understand this restraining behavior. In this work, both the open and closed mesopores inside coal with thermal treatment were investigated by low-temperature nitrogen adsorption and small angle X-ray scattering, and the molecular structure under corresponding conditions was characterized using Fourier transform infrared spectroscopy, 13C nuclear magnetic resonance, and X-ray diffraction. The results showed that the evolution of open mesopores with temperature exhibited a trend of decreasing and subsequently increasing, which was consistent with closed mesopores. These evolutions were affected by the adjustment of molecular structure during pyrolysis, and the effect was specifically divided in two stages. In the first stage (<500 °C), molecular structures such as aliphatic and oxygen were continuously removed affected by the decomposition reaction, resulting in a drastic reduction of the mesopores. In the second stage (>500 °C), molecular structure dominated by aromatic structures were continuously condensed under the influence of polycondensation reaction, leading to a gradual increase in mesopores.

On-Surface Boronation of Porphyrin into a Molecular Dipole.

Functionalized porphyrins by introducing exotic atoms into their central cavities have significant applications across various fields. As unique nanographenes, porphyrins functionalized with monoboron are intriguing, yet their synthesis remains highly challenging. Herein, we present the first on-surface boronation of porphyrin, bonding a single boron atom into the porphyrin's cavity. The boronation is selective, being observed exclusively in molecules featuring a specific aromatic ring-fused structure (ARFS*), not the pristine porphyrin molecule or its other ARFS forms. The boron's bonding geometry is noncentered, transforming the boronated porphyrin into a molecular dipole and imparting a markedly varied electronic structure. Well-ordered two-dimensional dipole arrays are achieved. Upon elevated thermoactivation, intermolecular O-B-O bonds provide robustness and flexibility to the molecular chains. This work demonstrates the high selectivity of on-surface porphyrin boronation and provides an effective strategy for tailoring molecules' electronic structure, producing molecular dipoles, and promoting the robustness and flexibility of molecular chains.

Exploring the graphitization transformation mechanism of deposited carbon in molten salt electrolysis: A novel insight from molecular structure models

Molten salt electrolysis graphitization is a novel method for the electrochemical graphitization, offering significant technological advantages. Researchers have shown keen interest in preparing graphite materials through molten salt strategies. However, there is still a lack of comprehensive research methodologies at the molecular scale for the removal of heteroatoms and rearrangement of carbon atoms in different amorphous carbon conversion systems. To address the above issue, the deposited carbon (DC, a coking byproduct) was converted into graphitized material (electrolysis products, EP) through the electrochemical method in this study. By processing Transmission Electron Microscope images with Python programming, aromatic skeleton structure information was quantitatively extracted. The evolution of the structure of DC was studied using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Based on information about elemental content, aromatic skeletal structure, and heteroatom functional groups, average chemical structure models were constructed for DC and EP, and relevant chemical bond parameters were statistically analyzed. Then, the influence of the electric field on the structural transformation of amorphous carbon in molten salts was investigated. The research results show that the electric field significantly affects the graphitization transformation process of amorphous carbon in molten salts, enhancing the interaction between calcium ions and DC molecules, increasing the diffusion coefficient of particles in the system, and promoting the formation of more sp2-hybridized carbon atoms, thus forming a more compact aromatic ring network. This study provides a new research method and molecular/atomic-level insights for a deeper understanding of the mechanism of graphitization transformation of amorphous carbon.

Harnessing the synergistic power of lignin-Ecoflex blends for enhanced performance in food packaging

In this study, a two-step chemical modification method was applied to lignin, enabling the thermal blending of lignin and Ecoflex® (PBAT) to produce films for food packaging applications. In the first step, 90 % of phenolic and carboxylic acid groups were converted into aliphatic hydroxy groups via hydroxyethylation, and in the second step, the aliphatic hydroxy groups were esterified with cinnamic acid, introducing abundant phenyl rings as well as unsaturated groups to the polymer. The modified lignin possessed an aliphatic–aromatic structure, similar to Ecoflex®, thereby enhancing the potential miscibility between these two materials. Subsequent experiments revealed that adding 20 % of modified lignin into Ecoflex® film resulted in the most significant improvement in mechanical properties, tripling the stiffness and doubling the strength. The addition of 30 % of modified lignin showed the best outcomes in UV absorption, barrier properties against oxygen and water vapor, and anti-oxidation ability. A strawberry ripening test indicated that the Ecoflex® film containing 30 % of modified lignin extended the shelf-life of strawberries from 2 days to 7 days, with better performance than the results of polyethylene bags and pure Ecoflex® films.

Spectroscopic characterization of black N- and P-doped zeolite templated carbons

The incorporation of heteroatoms (X) into the zeolite-templated carbon (ZTC) structure is a widely used technique to tailor its properties for specific applications such as gas adsorption, methane and hydrogen storage, and catalysis. However, the literature lacks sufficient data on Fourier-transform infrared spectroscopy (FTIR) analysis of ZTCs due to the challenge in obtaining high-quality FTIR spectra required for accurate assignment of the C–X bands, primarily caused by the black mass effect. In this work we prepared nitrogen (N) and phosphorus (P) doped ZTC samples using FAU type zeolite as a template and furfuryl alcohol as a carbon precursor. The Raman results confirmed the presence of medium-sized aromatic structures and also showed that doping these structures with N and P leads to some defects, although the overall conformation remains structurally intact. The FTIR spectra of the ZTC materials were obtained by controlling the preparation procedure and humidity, enabling clear analysis of the black samples. A Density Functional Theory (DFT) model based on the dimeric buckybowl structure was developed and complemented by experimental results obtained from X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and FTIR. The proposed DFT model was then used for deconvolution and precise band assignment of the experimental FTIR spectra. The FTIR deconvolution study also supported the incorporation of N and P into the ZTC as well as the presence of primarily two types of nitrogen species, amide (primary and secondary) and pyridine-like, while P was mainly incorporated as triphenylphosphine oxide and phosphonic acid.

Single‐Component High‐Resolution Dual‐Tone EUV Photoresists Based on Precision Self‐Immolative Polymers

Electron beam (EB) and extreme ultraviolet (EUV) lithography are advanced techniques capable of achieving sub‐10 nm resolutions, critical for fabricating next‐generation nanostructures and semiconductor devices. However, developing EUV photoresists that meet all demands for resolution, line edge roughness (LER), and sensitivity (RLS) remains a significant challenge. Herein, we introduce high‐performance photoresists based on single‐component self‐immolative polymers (SIPs) with inherent signal amplification via cascade degradation. These SIPs function as dual‐tone photoresists under both EB and EUV lithography, with performance primarily determined by the exposure dose. Lithographic evaluations show that discrete SIPs provide significant improvements over disperse counterparts, achieving higher resolution and reduced LER. Specifically, a discrete SIP with a DP of 12 produces a line‐space pattern with a resolution of approximately 18 nm and an LER of 1.8 nm, compared to 21 nm resolution and 2.5 nm LER for disperse SIPs. Additionally, these SIP‐based photoresists, enriched with aromatic structures, exhibit excellent etch resistance. The single‐component nature and potential to address the RLS trade‐off underscore the promise of discrete SIPs for EUV lithography.

A new insight into H-donor’s positive effect on thermal cracking process at molecular level

Thermal cracking reactions of vacuum residue (VR) at 420 ℃ with different reaction time were carried out to evaluate an industrial H-donor’s effect on thermal cracking process at molecular level. The mass distribution, conversion ratio, asphaltene and coke yields were analyzed to evaluate the changing rules. Aromatic structures of H-donor were analyzed and its typical structures were speculated, and the bond energy of those model compounds were calculated. It can be concluded that the >460℃ fractions from a refinery stream have abundant H-donors. From analyzing the structures of asphaltenes for the feed and products, it can be learned that H-donors not only can modify the asphaltene structures but also can improve the asphaltene solubility.

Coal pore size distribution and adsorption capacity controlled by the coalification in China

The coalification process significantly influences the composition of coal material and the development of pore size, ultimately affecting the adsorption capacity of coal seams and the extraction of coalbed methane. This project aimed to assess the pore structure and gas adsorption capacity of coal samples from nine key sedimentary basins in China. The N2 test results revealed that during the initial stage of coalification, micropore, transition pore, and mesopore dominate in order of magnitude. In the subsequent coalification stages, the development of mesopore is most significant during the second jump, while the transition pore becomes more prominent in the third jump. Additionally, the findings from nuclear magnetic resonance tests indicate that the proportion of adsorbed pore demonstrates a decreasing-then-increasing trend throughout the coalification process. The first and second coalification jumps primarily contribute to the development of adsorption pore and seepage pore, whereas the third jump mainly focuses on adsorption pore development. The gas adsorption capacity is influenced by various factors such as pore structure, material composition, and chemical structure. During the first coalification jump, gas adsorption mainly occurs in the adsorption pore. In the second jump, medium gas adsorption capacity is achieved due to the combined effects of enhanced adsorption pore development and reduced moisture and ash content. Finally, the third coalification jump exhibits highly developed adsorption pores, the lowest moisture and ash levels, and a sufficient aromatic structure in the chemical composition, resulting in high adsorption capacity. These findings contribute to a deeper understanding of the variations in coalbed methane enrichment across different basins in China, with coalification playing a crucial controlling role.

11-Azaartemisinin derivatives bearing halogenated aromatic moieties: Potent anticancer agents with high tumor selectivity

While artemisinin and its derivatives, including 11-azaartemisinin-based compounds, have shown promising anticancer activity, the integration of halogens into aromatic structures can amplify drug potency, metabolic stability, and selectivity. Herein, we present the synthesis of new novel 11-azaartemisinin derivatives bearing halogenated aromatic moieties connected via 1,2,3‐triazole bridges and evaluate their anticancer activities against three human tumor cell lines: epidermoid carcinoma (KB), hepatocellular carcinoma (HepG2), and human lung adenocarcinoma (A549). Among the synthesized compounds, six of them (8c-h) displayed good to excellent antiproliferative activity in the low micromolar range across all three human cancer cell lines. In general, the m-bromide (8c) and m-iodide (8d) compounds exhibited superior anticancer activities compared to their o- and p-analogs, as well as the m-chloride and m-fluoride compounds. The most promising m-Br compound (8c) displayed 50 % inhibition of KB, HepG2, and A549 cell growth at concentrations of 7.7, 42.5, and 15.5 μM, respectively. Notably, the m-Br compound (8c) exhibited approximately 32-, 6-, and 16-fold lower activity in normal cells (Hek293) compared to KB, HepG2, and A549 tumor cells, respectively, indicating a significant tumor-selectivity.

Long-term biochar and soil organic carbon stability – Evidence from field experiments in Germany

Organic soil amendments (OSA) with long residence times, such as biochar, have a high potential for soil organic carbon (SOC) sequestration. The highly aromatic structure of biochar reduces microbial decomposition and explains the slow turnover of biochar, indicating long persistence in soils and thus potential SOC sequestration. However, there is a lack of data on biochar-induced SOC sequestration in the long-term and under field conditions. We sampled two long-term field experiments in Germany, where biochar was applied 12 and 14 years ago. Both locations differ in soil characteristics and in the types and amounts of biochar and other OSA. Amendments containing compost and 31.5 Mg ha−1 of biochar on a loamy soil led to a SOC stock increase of 38 Mg ha−1 after OSA addition. The additional increase is due to non-biochar co-amendments such as compost or biogas digestate. After eleven years, this SOC stock increase was still stable. High biochar amount additions of 40 Mg ha−1 combined with biogas digestate, compost or synthetic fertilizer on a sandy soil led to an increase of SOC stocks of 61 Mg ha−1; 38 Mg ha−1 dissipated in the following four years most likely due to lacking physical protection of the coarse soil material, and after nine years the biochar-amended soils showed only slightly higher SOC stocks (+7 Mg ha−1) than the control. Black carbon stocks on the same soil increased in the short- and mid-term and decreased almost to the original stock levels after nine years. Our results indicate that in most cases the long-term effect on SOC and black carbon stocks is controlled by biochar quality and amount, while non-biochar co-amendments can be neglected. This study proves that SOC sequestration through the use of biochar is possible, especially in loamy soils, while non-biochar OSA cannot sequester SOC in the long term.

Microcrystalline Engineering of Anthracite-Based Carbon Via Salt-Assisted Ball Milling for Enhanced Sodium Storage Performance.

Coal-based carbon material, characterized by abundant resources and low cost, has gained considerable interests as a promising anode candidate for sodium-ion batteries (SIBs). However, the coal-based carbon generally shows inferior Na-storage performance due to its highly-ordered microstructure with narrow interlayer spacing. Herein, a salt-assisted mechanical ball-milling strategy is proposed to disrupt the polycyclic aromatic hydrocarbon structure in anthracite molecules, thereby reducing the microcrystalline regularity of the derived carbon during following pyrolysis process. In addition, the induced C─O─C bonds during ball-milling process can alter the pyrolysis behavior of anthracite and restrain the formation of surface defects. Consequently, in contrast to pristine anthracite-based pyrolytic carbon, which exhibits a Na-storage capacity of 198.4 mAh g-1 with a low initial Coulombic efficiency (ICE) of 65.1%, the ball-milling modified carbon assisted by NaCl salt (NAC), with enhanced structural disordering and reduced surface defects, demonstrate significantly improved Na-storage capacity of 332.1 mAh g-1 and ICE value of 82.0%. The NAC electrode also realizes excellent cycle and rate performance, retaining a capacity of 196.0 mAh g-1 at 1 C after 1000 cycles. Furthermore, when coupled with NaNi1/3Fe1/3Mn1/3O2 cathode, the assembled Na-ion full cell deliveres an exceptional electrochemical performance, highlighting its promising prospect as high-performance anode for SIBs.

Deeper insights into flame retardancy of polymers by interpretable, quantifiable, yet accurate machine-learning model

Fire-safety polymer materials are essential in modern society such as electronics, aerospace, new energy. The quantification and prediction of flame retardancy, determined by the chemical composition and the burning process, has always been a bottleneck challenge. Previous empirical design rules and the existing models show large deviations for predicting flame retardancy and are often unexplainable. Here, this study proposes an interpretable model that can quantify the groups contribution of flame-retardancy and predict the flame retardance of intrinsically flame-retardant polymers. The machine learning model simultaneously considers the group structures and their flame-retardant mechanism in both the gas phase and condensed phase, achieving high prediction accuracy (89.8% for the training set and 83.8% for the testing set). It also quantifies the contribution values of various flame-retardant groups (halogen-containing structures, phosphorus-containing structures, phosphorus-nitrogen-containing structures, aromatic ring-containing structures, etc.) in both phases for the first time. The running script that integrates the model has also been open-sourced, providing an emerging strategy for transitioning flame-retardant research from empirical methods to scientific design.

C–H/C–H Aromative carbonylation of diarylalkynes enabled palladium-catalyzed by 6-endo-dig carbocyclization

Transition metal-catalyzed cycloaromatization reactions of diarylalkynes offer a swift and versatile approach to synthesizing a wide array of polycyclic aromatic compounds. However, the specific mechanism of Pd-catalyzed C–H/C–H aromative carbonylation of diarylalkynes, particularly those bearing adjacent functional groups, remains a relatively unexplored area. Herein, we present a palladium-catalyzed C–H/C–H aromative carbonylation of diarylalkynes, which proceeds through an exclusive 6-endo-dig carbocyclization pathway, followed by the incorporation of CO to yield carbonyl compounds. This methodology provides a novel and efficient route for generating complex aromatic structures, thus expanding the potential applications in organic synthesis.

Degradation of toxic components in kitchen waste during hydrothermal carbonization process

Hydrothermal carbonization (HTC) is a promising technique for kitchen waste (KW) disposal. However, KW may contain heavy metals (HMs), aflatoxin, nitrites and sulfites, posing risk for hydrochar utilization. In order to clarify the migration of these toxic components during hydrochar formation process, 7 kinds of kitchen wastes were adopted to carry out HTC experiments at 180–240 °C. Concentration detections results showed that Fe, Mn, Cr, Ni, Cu, and Zn contents were relatively high with a range of 30–2500 mg/kg in KW feedstocks. After HTC treatment, Fe, Cr, Cu were mainly (>80 %) enriched in hydrochar, the enrichment factors of Mn, Ni, Zn was almost above 50 %. From the perspective of species and valence distributions, Mn, Fe, Ni, and Zn in hydrochar were below moderate risk level. No aflatoxin was detected in hydrochar, because AFB1 and AFB2 can be completely degraded into organic acids in the HTC environment at 180 °C. Part benzene rings in aflatoxin were reduced and the C-C bonds were further broken, the C-O bonds were oxidized to produce carboxylic acids. Some benzene rings in aflatoxin remained to form organic acids with aromatic structures. NO2− and SO32- ions with strong ecotoxicity were mostly converted into NO3− and SO42- and flowed into the liquid phase. Some NO2− ions were also converted to and ammonia N and pyridine N; some SO32- ions were converted to sulfonic and sulfinic acid organics, which were successively transformed into sulfonyl/sulfinyl and sulfone/sulfoxide organics. The above findings are of great significance for the transformation mechanism of toxic substances in HTC environment and environment-friendly utilization of hydrochar.

Uncovering the performance and intrinsic mechanism of different hydrolyzed AlTi species in polystyrene nanoplastics coagulation

Hydrolyzed AlTi species are essential metal-based coagulants in a coagulation process to remove nanoplastics (NPs). Understanding the molecular interactions between hydrolyzed AlTi species and NPs is key to promoting coagulation efficiency. In this study, the coagulation performance and intrinsic mechanism of different AlTi species (including monomeric AlTi and polymeric AlTi species-Al13Ti13) for NPs removal were systematically investigated. We found that the polymeric AlTi species exhibited higher turbidity removal (95.0 %) and lower residual Al content (20.67 μg/L) at a low dosage over monomeric AlTi species. Al13 and Al13Ti13 formed by in situ hydrolysis were the dominant species to destabilize and aggregate NPs at pH 6. Main coagulation mechanisms were dominated by charge neutralization, complexation between the aliphatic CH of NPs and Al/Ti-OH, and cation-π interaction between polycations and the aromatic structure of NPs. The preformed Al13Ti13 showed multiple positive charge binding sites assisting its easy adsorption on NPs by electrostatic attraction, and then formed microscale aggregates through charge neutralization or intermolecular interaction. The preformed Al13Ti13 demonstrated a high stability and coagulation performance with respect to pH changes in raw water, whereas the promotion of μ-OH bridges dissociation by OH− and the presence of electrostatic repulsion significantly decreased the NPs removal by monomeric AlTi at high pH. This study provides valuable theoretical insights into the interaction between NPs and various hydrolyzed AlTi species.

Evolution mechanism of coal chemical structure after supercritical CO2 transient fracturing

This study investigates the chemical structural evolution of coal during supercritical CO2 transient fracturing using a self-developed experimental platform. Coal samples with different metamorphic ranks were subjected to transient fracturing under different pressures. Characterization techniques, including X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy, analyzed the fractured coal samples. Initially, supercritical CO2 dissolved minerals and non-aromatic structures, rearranging organic compounds. As fracturing intensified, alkanes and substituents rapidly released, causing large aromatic rings to break into smaller ones. The breakage of small aromatic rings created pores and increased aromatic structure dimensions. Moreover, the interaction between fractured small aromatic rings and oxygen atoms in the C=O group facilitated the formation of new C–C bonds, promoting the connection of aromatic rings to form larger structures. In the early stages of fracturing, the molecular structure of coal relaxed, and subsequently, as the fracturing intensified, the hydrogen bonds initially broken could reconnect to aromatic structures to form OH-π interactions, enhancing intermolecular attraction. This promoted molecules to be more inclined to form stable, dense structures. Understanding this evolution mechanism aids in analyzing the transformation of fractured coal pores, thereby enhancing our understanding of the mechanism for improving coal seam permeability using this technology.

Catalytic depolymerization and hydrodeoxygenation of lignin to high-density fuel precursors using Ni/Nb2O5 catalyst

Converting lignin into renewable fuels via hydrogenolysis is crucial for achieving carbon neutrality. Existing methods primarily produce monomers in the carbon range of 6–9, inadequate for sustainable aviation fuels requiring heavier components. This study introduces a Ni/Nb2O5 catalyst for catalytic transfer hydrogenolysis of organosolv birch lignin with isopropanol, predominantly resulting in dimers and trimers within carbon ranges of 8–16 and 16–30, comprising 24.7 % and 60.5 % of the lignin-oil, respectively. The catalyst's oxygen vacancies and acid sites facilitate efficient C-O and C-C bonds cleavage, preserving a highly aromatic structure with reduced O/C ratio, elevated H/C ratio, and decreased unsaturation. Characterization techniques confirm a significant 55.5 % deoxygenation degree of the lignin-oil, making it suitable for the synthesis of customized fuel across various carbon numbers. This approach offers a practical pathway for obtaining renewable heavier fuel components and precursors from lignin, significantly advancing sustainable fuel technologies.

Exploiting Lignin Structure and Reactivity to Design Vitrimers with Controlled Ratio of Dynamic to Non-Dynamic Bonds.

Lignin is an abundant biobased feedstock, representing the first source of renewable aromatic structures. Thanks to its high functionality in aliphatic hydroxyls (Al-OH), phenolic hydroxyls (Ph-OH) and carboxylic acids (COOH), lignin is an attractive precursor to crosslinked polymer materials. Different biobased macromolecular architectures can be designed from lignins, whose end-of-life should also be considered in the context of a circular bioeconomy. To enhance recyclability of crosslinked polymer networks, the introduction of dynamic linkages to design vitrimers is a promising strategy. In this study, Kraft lignin was chemically modified with succinic anhydride, to prepare a series of modified lignins with a controlled COOH/Ph-OH ratio, exploiting the difference in reactivity between Al-OH and Ph-OH groups. Upon crosslinking with a diepoxy, mixed vitrimer networks with variable ratios between dynamic ester bonds and non-dynamic ether bonds were synthesized. The analysis of their properties evidenced the impact of the non-dynamic linkages on the materials behaviors, including their dynamicity and reprocessing ability. Although the activation energy for bond exchange is increased, non-dynamic linkages do not hinder the reprocessability of these adaptable materials, and provide them high creep resistance. The controlled introduction of non-dynamic linkages appears as a promising strategy to enhance the properties of lignin-based vitrimers.

Simultaneously reducing methane emissions and arsenic mobility by birnessite in flooded paddy soil: Overlooked key role of organic polymerisation

Flooding of paddy fields enhances methane (CH4) emissions and arsenic (As) mobilisation, which are crucial issues for agricultural greenhouse gas emissions and food safety. Birnessite (δ-MnO2) is a common natural oxidant and scavenger for heavy metals. In this study, birnessite was applied to As-contaminated paddy soil. The capacity for simultaneously alleviating CH4 emissions and As mobility was explored. Soil microcosm incubation results indicated that birnessite addition simultaneously reduced CH4 emissions by 47 %–54 % and As release by 38 %–85 %. The addition of birnessite decreased the dissolved organic carbon (DOC) contents and altered its chemical properties. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) results showed that birnessite reduced the labile fractions of proteins, carbohydrates, lignins, tannins, and unsaturated hydrocarbons, however, increased the abundance of condensed aromatic structures, suggesting the polymerisation of dissolved organic matter (DOM) by birnessite. The degradation of labile fractions and the polymerisation of DOM resulted in an inventory of recalcitrant DOM, which is difficult for microbes to metabolise, thus inhibiting methanogenesis. In contrast, birnessite addition increased CH4 oxidation, as the particulate methane monooxygenase (pmoA) gene abundance increased by 30 %. The enhanced polymerisation of DOM by birnessite also increased As complexation with organics, leading to the transfer of As to the organic bound phase. In addition, the decrease in ferrous ion [Fe(II)] concentrations with birnessite indicated that the reductive dissolution of Fe oxides was suppressed, which limited the release of arsenite [As(III)] under reducing conditions. Furthermore, birnessite decreased As methylation and shaped the soil microbial community structure by enriching the metal-reducing bacterium Bacillus. Overall, our results provide a promising method to suppress greenhouse gas emissions and the risk of As contamination in paddy soils, although further studies are needed to verify its efficacy and effectiveness under field conditions.

Coconut Shell Carbon Preparation for Rhodamine B Adsorption and Mechanism Study.

Phosphoric acid is used as a chemical activator to prepare coconut shell carbon (PCSC), and for investigating rhodamine B (RhB) adsorption performance. The optimal conditions for the preparation of PCSC (calcined temperature, phosphoric acid concentration), and the influence of adsorption conditions (concentration, pH, etc.) on RhB and the recovery performance of optimal carbon are investigated. Experimental results show that when the amount of PCSC (600 °C, 2 h) is 0.2 g, the initial RhB concentration is 10 mg/L, pH = 6, and the adsorption time is 30 min, it can have 95.84% RhB adsorption efficiency. Liquid ultraviolet spectroscopy also supports this adsorption performance. Characterization data showed that hydroxyl and ester groups, aromatic structures, and PO43- existed on the surface of PCSC, and the amount decreased with increasing calcined temperature. PCSC has a BET (N2) surface area of 408.59 m2/g and has a micropore distribution, EDS-detected P content is 3.91%. SEM showed that the PCSC formed micropores which could better adsorb RhB. The kinetic and thermodynamic analysis of the adsorption of RhB by PCSC showed that the adsorption process was in accord with quasi-secondary kinetic equations and ΔGθ was between -1.65 and -18.75 kJ/mol. The adsorption was a physical adsorption and a spontaneous endothermic reaction, and the obtained PCSC sorption isotherms were classified as Langmuir-type. The RhB adsorption mechanism on PCSC includes pore diffusion, hydrogen bonding, and π-π conjugation. The PCSC prepared by H3PO4 modification has superior adsorption and recycling performance for RhB, providing a reference for the preparation of other biomass carbon materials for the treatment of dye wastewater.