Boron-Nitrogen-Edged Biomass-Derived Carbon: A Multifunctional Approach for Colorimetric Detection of H2O2, Flame Retardancy, and Triboelectric Nanogenerator

Enhancing the concentration and type of nitrogen (N) dopants within the Sp2-carbon domain of carbon recycled from biomass sources is an efficient approach to mimic CNT, GO, and rGO to activate oxidants such as H2O2, excluding toxic chemicals and limiting reaction steps. However, monitoring the kind and concentration of N species in the Sp2-C domain is unlikely with thermal treatments only. A high temperature for graphitization reduces N moieties, leading to low electron density. This inhibits H2O2 adsorption and activation on catalyst surfaces. In this study, coffee waste (CW) is converted into B, N-doped biochar (BXNbY) using boric acid-assisted pyrolysis (H3BO3 mass = X and carbonization temperature = Y) under N2 to overcome the challenge. The B dopant regulates the concentration and type of N, provides Lewis's acid sites, and converts graphitic-N to pyridine-N in BXNbY. The optimized B3Nb900 exhibits excellent colorimetric sensing performance toward H2O2 with a low detection limit (36.9 nM) and high selectivity in the presence of many interferences and milk samples due to high pyridinic-N and Sp2 domain sizes. Interestingly, B enhances other properties of N-containing CW-derived carbon and introduces self-extinguishing and tribopositive properties. Hence, BXNbY-coated polyurethane foam shows excellent flame retardancy and energy harvesting performance.

Functional biochar accelerates peroxymonosulfate activation for organic contaminant degradation via the specific B-C-N configuration

Functional biochar designed with heteroatom doping facilitates the activation of peroxymonosulfate (PMS), triggering both radical and non-radical systems and thus augmenting pollutant degradation efficiency. A sequence of functional biochar, derived from hyperaccumulator (Sedum alfredii) residues, was synthesized via sequential doping with boron and nitrogen. The SABC-B@N-2 exhibited outstanding catalytic effectiveness in activating PMS to degrade the model pollutant, acid orange 7 (Kobs = 0.0655 min-1), which was 6.75 times more active than the pristine biochar and achieved notable mineralization efficiency (71.98%) at reduced PMS concentration (0.1 mM). Relative contribution evaluations, using steady-state concentrations combined with electrochemical and in situ Raman analyses, reveal that co-doping with boron and nitrogen alters the reaction pathway, transitioning from PMS activation through multiple reactive oxygen species (ROSs) to a predominantly non-radical process facilitated by electron transfer. Moreover, the previously misunderstood concept that singlet oxygen (1O2) plays a central role in the degradation of AO7 has been clarified. Correlation analysis and density functional theory calculations indicate that the distinct BCN configuration, featuring the BC2O group and pyridinic-N, is fundamental to the active site. This research substantially advances the sustainability of phytoremediation by offering a viable methodology to synthesize highly catalytic functional biochar utilizing hyperaccumulator residues.

Enzymolytic Lignin-Derived N-S Codoped Porous Carbon Nanocomposites as Electrocatalysts for Oxygen Reduction Reactions

Currently, the development of nonmetallic oxygen reduction reaction (ORR) catalysts based on heteroatomic-doped carbon materials is receiving increaseing attention in the field of fuel cells. Here, we used enzymolytic lignin (EL), melamine, and thiourea as carbon, nitrogen, and sulfur sources and NH4Cl as an activator to prepare N- and S-codoped lignin-based polyporous carbon (ELC) by one-step pyrolysis. The prepared lignin-derived biocarbon material (ELC-1-900) possessed a high specific surface area (844 m2 g-1), abundant mesoporous structure, and a large pore volume (0.587 cm3 g-1). The XPS results showed that ELC-1-900 was successfully doped with N and S. ELC-1-900 exhibited extremely high activity and stability in alkaline media for the ORR, with a half-wave potential (E1/2 = 0.88 V) and starting potential (Eonset = 0.98 V) superior to those of Pt/C catalysts and most non-noble-metal catalysts reported in recent studies. In addition, ELC-1-900 showed better ORR stability and methanol tolerance in alkaline media than commercial Pt/C catalysts.

Engineering of Local Coordination Microenvironment in Single-Atom Catalysts Enabling Sustainable Conversion of Biomass into a Broad Range of Amines

Utilizing renewable biomass as a substitute for fossil resources to produce high-value chemicals with a low carbon footprint is an effective strategy for achieving a carbon-neutral society. Production of chemicals via single-atom catalysis is an attractive proposition due to its remarkable selectivity and high atomic efficiency. In this work, a supramolecular-controlled pyrolysis strategy is employed to fabricate a palladium single-atom (Pd1 /BNC) catalyst with B-doped Pd-Nx atomic configuration. Owing to the meticulously tailored local coordination microenvironment, the as-synthesized Pd1 /BNC catalyst exhibits remarkable conversion capability for a wide range of biomass-derived aldehydes/ketones. Thorough characterizations and density functional theory calculations reveal that the highly polar metal-N-B site, formed between the central Pd single atom and its adjacent N and B atoms, promotes hydrogen activation from the donor (reductants) and hydrogen transfer to the acceptor (C═O group), consequently leading to exceptional selectivity. This system can be further extended to directly synthesize various aromatic and furonic amines from renewable lignocellulosic biomass, with their greenhouse gas emission potentials being negative in comparison to those of fossil-fuel resource-based amines. This research presents a highly effective and sustainable methodology for constructing C─N bonds, enabling the production of a diverse array of amines from carbon-neutral biomass resources.

Comparative effect of mesoporous carbon doping on the adsorption of pharmaceutical drugs in water: Theoretical calculations and mechanism study

In this study, mesoporous doped-carbons were synthesized from sucrose, a natural source, boric acid and cyanamide as precursors, generating B- or N-doped carbon. These materials were characterized by FTIR, XRD, TGA, Raman, SEM, TEM, BET, and XPS, confirming the preparation of a tridimensional doped porous structure. B-MPC and N-MPC showed a high surface specific area above 1000 m²/g. The effect of B and N doping on mesoporous carbon was evaluated on the adsorption of emerging pollutants from water. Diclofenac sodium and paracetamol were used in adsorption assays, reaching removal capacities of 78 and 101 mg.g^-1, respectively. Kinetic and isothermal studies indicate the chemical nature of adsorption controlled by external and intraparticle diffusion and multilayer formation due to strong adsorbent/adsorbate interactions. DFT-based calculations and adsorption assays infer that the main attractive forces are hydrogen bonds and Lewis acid-base interactions.

B,N-decorated carbocatalyst based on Fe-MOF/BN as an efficient peroxymonosulfate activator for bisphenol A degradation

A novel B,N-decorated carbocatalyst (Fe@BPC-XBN) for peroxymonosulfate (PMS) activation was prepared by a simple pyrolysis method using the iron-based metal organic frameworks (Fe-MOF), boric acid and boron nitride (BN) as precursors. Fe@BPC-20BN removed 93.3% of bisphenol A (BPA) in 90 min compared to 64.9%, 82.1% and 83.5% with Fe@PC, Fe@BPC and Fe@PC-20BN, respectively, with 0.15 g/L catalyst and 1 mM PMS at initial pH of 7. The solo B-doping with boron acid on the Fe-MOF derived porous carbon enhanced its catalytic capacity; moreover, B, N co-doping with BN and boron acid as precursors further promoted the catalytic performance. The addition of BN not only provided more B, N catalytic centers but also improved the stability of the carbocatalyst. In addition, hydroxyl radicals, sulfate radicals, superoxide radicals, and singlet oxygen species were involved in the degradation of BPA. Fe species, -BCO₂/-BC₂O, pyridinic N, and pyrrolic N groups on the carbon matrix played the important roles in the BPA degradation. The outstanding catalytic performance of Fe@BPC-20BN could be attributed to the synergistic effects between iron nanoparticles and the B/N codoped carbon matrix. This study gives new insights into the design and preparation of high-efficient B,N-decorated carbocatalysts for environmental remediation.

In Vitro and In Vivo Biocompatibility of Boron/Nitrogen Co-Doped Carbon Nano-Onions

Boron/nitrogen, co-doped, carbon nano-onions (BN-CNOs) have recently shown great promise as catalysts for the oxygen reduction reaction, due to the improved electronic properties imparted by the dopant atoms; however, the interactions of BN-CNOs with biological systems have not yet been explored. In this study, we examined the toxicological profiles of BN-CNOs and oxidized BN-CNOs (oxi-BN-CNOs) in vitro in both healthy and cancer cell lines, as well as on the embryonic stages of zebrafish (Danio rerio) in vivo. The cell viabilities of both cell lines cells were not affected after treatment with different concentrations of both doped CNO derivatives. On the other hand, the analysis of BN-CNOs and oxidized BN-CNO interactions with zebrafish embryos did not report any kind of perturbations, in agreement with the in vitro results. Our results show that both doped CNO derivatives possess a high biocompatibility and biosafety in cells and more complex systems.

Linking the Defective Structure of Boron-Doped Carbon Nano-Onions with Their Catalytic Properties: Experimental and Theoretical Studies

Defects are widely present in nanomaterials, and they are recognized as the active sites that tune surface properties in the local region for catalysis. Recently, the theory linking defect structures and catalytic properties of nanocatalysts has been most commonly described. In this study, we prepared boron-doped carbon nano-onions (B-CNOs) by applying an annealing treatment of ultradispersed nanodiamond particles and amorphous boron. These experimental conditions guarantee doping of CNOs with boron atoms in the entire carbon nanostructure, thereby ensuring structural homogeneity. In our research, we discuss the correlations between defective structures of B-CNOs with their catalytic properties toward SO₂ and tert-butanol dehydration. We show that there is a close relationship between the catalytic properties of the B-CNOs and the experimental conditions for their formation. It is not only the mass of the substrates used for the formation of B-CNOs that is crucial, that is, the mass ratio of NDs to amorphous B, but also the process, including temperature and gas atmosphere. As it was expected, all B-CNOs demonstrated significant catalytic activity in HSO₃^- oxidation. However, the subsequent annealing in an air atmosphere diminished their catalytic activity. Unfortunately, no direct relationship between the catalytic activity and the presence of heteroatoms on the B-CNO surface was observed. There was a linear dependence between catalytic activity and Raman reactivity factors for each of the B-CNO materials. In contrast to SO₂ oxidation, the B-CNO-a samples showed higher catalytic activity in tert-butanol dehydration due to the presence of Brønsted and Lewis acid sites. The occurence of three types of boron-Lewis sites differing in electron donor properties was confirmed using quantitative infrared spectroscopic measurements of pyridine adsorption.

Integrating single-cobalt-site and electric field of boron nitride in dechlorination electrocatalysts by bioinspired design

The construction of enzyme-inspired artificial catalysts with enzyme-like active sites and microenvironment remains a great challenge. Herein, we report a single-atomic-site Co catalyst supported by carbon doped boron nitride (BCN) with locally polarized B-N bonds (Co SAs/BCN) to simulate the reductive dehalogenases. Density functional theory analysis suggests that the BCN supports, featured with ionic characteristics, provide additional electric field effect compared with graphitic carbon or N-doped carbon (CN), which could facilitate the adsorption of polarized organochlorides. Consistent with the theoretical results, the Co SAs/BCN catalyst delivers a high activity with nearly complete dechlorination (~98%) at a potential of -0.9 V versus Ag/AgCl for chloramphenicol (CAP), showing that the rate constant (k) contributed by unit mass of metal (k/ratio) is 4 and 19 times more active than those of the Co SAs/CN and state-of-the-art Pd/C catalyst, respectively. We show that Co single atoms coupled with BCN host exhibit high stability and selectivity in CAP dechlorination and suppress the competing hydrogen evolution reaction, endowing the Co SAs/BCN as a candidate for sustainable conversion of organic chloride.

Highly Rechargeable Lithium-CO2 Batteries with a Boron- and Nitrogen-Codoped Holey-Graphene Cathode

Metal-air batteries, especially Li-air batteries, have attracted significant research attention in the past decade. However, the electrochemical reactions between CO₂ (0.04 % in ambient air) with Li anode may lead to the irreversible formation of insulating Li₂ CO₃ , making the battery less rechargeable. To make the Li-CO₂ batteries usable under ambient conditions, it is critical to develop highly efficient catalysts for the CO₂ reduction and evolution reactions and investigate the electrochemical behavior of Li-CO₂ batteries. Here, we demonstrate a rechargeable Li-CO₂ battery with a high reversibility by using B,N-codoped holey graphene as a highly efficient catalyst for CO₂ reduction and evolution reactions. Benefiting from the unique porous holey nanostructure and high catalytic activity of the cathode, the as-prepared Li-CO₂ batteries exhibit high reversibility, low polarization, excellent rate performance, and superior long-term cycling stability over 200 cycles at a high current density of 1.0 A g^-1 . Our results open up new possibilities for the development of long-term Li-air batteries reusable under ambient conditions, and the utilization and storage of CO₂ .

Sodium-Ion Batteries: Improving the Rate Capability of 3D Interconnected Carbon Nanofibers Thin Film by Boron, Nitrogen Dual-Doping

Boron, nitrogen dual-doping 3D hard carbon nanofibers thin film is synthesized using a facile process. The nanofibers exhibit high specific capacity and remarkable high-rate capability due to the synergistic effect of 3D porous structure, large surface area, and enlarged carbon layer spacing, and the B, N codoping-induced defects.

Boron–manganese–carbon nanocomposites synthesized from CO2 for electrode applications in both supercapacitors and fuel cells

Boron–manganese–carbon nanocomposites were synthesized from CO₂ for electrode materials in supercapacitor and fuel cell.

Constructing B and N separately co-doped carbon nanocapsules-wrapped Fe/Fe3C for oxygen reduction reaction with high current density

The exploration of low-cost and highly efficient non-platinum electrocatalysts for the oxygen reduction reaction (ORR) is vital for renewable systems.

Enhanced oxygen reduction from the insertion of cobalt into nitrogen-doped porous carbons

Enhanced oxygen reduction reaction activity by impregnating Co₃O₄ to N-doped porous carbons.

Boron and phosphorous-doped graphene as a metal-free electrocatalyst for the oxygen reduction reaction in alkaline medium

Phosphorous and boron-doped graphene, prepared using a single precursor, showed reasonable oxygen reduction activity and excellent stability in alkaline electrolyte.