Functionalized Carbon Nanomaterials Research Articles

Enhancing Efficiency and Stability in Carbon-Based Perovskite Solar Cells by Double Passivation with Ultralow-Cost Coal-Derived Graphene and Its Derivatives.

Coal-derived carbon nanomaterials possess numerous superior features compared to other classic carbon, such as readily accessible surfaces, tunable pore structure, and facile and precise surface functionalization. Therefore, the controllable preparation of coal-derived carbon nanomaterials is anticipated to be of great significance for the performance improvement and commercialization process of carbon-based perovskite solar cells (C-PSCs). In this study, we successfully synthesized highly stable and commercially valuable graphene oxide (GO) and reduced graphene oxide (rGO) utilizing coal. Compared to traditional methods and commercial graphene, the chemical oxidation and pyrolysis process used in this study is mild and simple, offering the advantages of controlled composition and the absence of other impurities. GO or rGO was incorporated into the top of the SnO2 electron transport layer (ETL) of C-PSCs. Under optimized conditions and ultraviolet-ozone (UVO) irradiation, the ultimate power conversion efficiency (PCE) increased from the unmodified 12.4 to 14.04% (based on rGO) and 15.18% (based on GO), representing improvements of 22 and 31%, respectively. The improved photovoltaic performance is mainly owing to enhanced charge transport capabilities, denser interfacial contacts, improved carrier separation properties, increased conductivity, and abundance of hydrophilic functional groups in GO, which can form more stable hydrogen bonds with SnO2. After being stored at room temperature and ambient humidity for 30 days, the modified, unpacked devices retained 87% of the highest power conversion efficiency (PCE). This study introduces a practical and manageable method to enhance the performance of C-PSCs by using functional carbon nanomaterials derived from coal.

Pinecone derived hierarchical carbon nanostructure as a transducer in a solid-state ion-selective electrode for in vivo analysis of calcium ion

Monitoring extracellular calcium ion (Ca2+) chemical signals in neurons is crucial for tracking physiological and pathological changes associated with brain diseases in live animals. Potentiometry based solid-state ion-selective electrodes (ISEs) with the assist of functional carbon nanomaterials as ideal solid-contact layer could realize the potential response for in vitro and in vivo analysis. Herein, we employ a kind of biomass derived porous carbon as a transducing layer to prompt efficient ion to electron transduction while stabilizes the potential drift. The eco-friendly porous carbon after activation (APB) displays a high specific area with inherit macropores, micropores, and large specific capacitance. When employed as transducer in ISEs, a stable potential response, minimized potential drift can be obtained. Benefiting from these excellent properties, a solid-state Ca2+ selective carbon fiber electrodes (CFEs) with a sandwich structure is constructed and employed for real time sensing of Ca2+ under electrical stimulation. This study presents a new approach to develop sustainable and versatile transducers in solid-state ISEs, a crucial way for in vivo sensing.

Natural biochar catalyst: Realizing the co-valorization of waste cooking oil into high-quality biofuel and carbon nanotube precursor via catalytic pyrolysis process

Valorizing renewable precursors into high-quality biofuel and functional carbon nanomaterials can considerably improve the economic viability. Here, we propose a process for integrated production of high-quality biofuel and carbon nanotubes from waste cooking oil via catalytic pyrolysis coupling with chemical vapor deposition (CVD) technology. The natural biochar catalyst demonstrates excellent deoxygenation performance and good stability in catalytic pyrolysis process. The alkali/alkaline earth metal species (AAEMs) content in biochar catalysts has a strong correlation with the selectivity of esters and hydrocarbons in bio-oil. The biofuel obtained under optimal conditions exhibited potential as a precursor for jet fuel. The CVD process convert pyrolysis gas into carbon nanotubes with yield of 2.13%. The technical–economic analysis demonstrated the feasibility of the integrated process, projecting profitability and substantial total profit over a ten-year period. Overall, this study improves the economic viability of the waste cooking oil pyrolysis process and supports its wider commercial application.

Upcycling of waste poly(lactic acid) into crumped carbon nanosheet towards high-performance interfacial solar-driven evaporation

The controllable carbonization of waste plastics into functional carbon nanomaterials towards environmental remediation, energy conversion and storage has received widespread attention. However, there are few studies on the carbonization of poly(lactic acid) (PLA) into porous carbon. Herein, the controlled carbonization of PLA into crumped carbon nanosheet (CCN) is reported. Firstly, recycled PLA bags are converted into magnesium-based metal-organic framework (Mg-MOF) through the combined strategy of mechanochemical milling and solution mixing, and then Mg-MOF is transformed into CCN through the metal-organic framework (MOF)-assisted carbonization strategy. CCN exhibits merits of abundant nanopores and oxygen-containing groups. As a result, the CCN-derived evaporator holds good light absorptivity, low evaporation enthalpy, and good light-to-thermal conversion ability. Furthermore, the CCN-derived solar evaporator achieves a high evaporation rate (2.70 kg m−2 h−1) at 1 kW m−2 irradiation, along with good long-term stability, which surpasses many recent advanced solar evaporators. Noteworthy, when wastewater, lake water, seawater, tetracycline solution, and dye-polluted water are used, the CCN-based evaporator remains high performance in freshwater production. Importantly, an outdoor CCN-based device is constructed, which realizes the freshwater production of 6.3 kg m−2. The collected freshwater can cultivate well mung bean sprouts under natural condition. This work not only provides a new "turning-waste-into-treasure" method for the recycling of waste PLA, but also offers a novel strategy for the preparation of low-cost, functional carbon materials for diverse applications.

Sustainability, performance, and production perspectives of waste-derived functional carbon nanomaterials towards a sustainable environment: A review

The survival of humanity is severely threatened by the massive accumulation of waste in the ecosystem. One plausible solution for the management and upcycling of waste is conversing waste at the molecular level and deriving carbon-based nanomaterial. The field of carbon nanomaterials with distinctive properties, such as exceptionally large surface areas, good thermal and chemical stability, and improved propagation of charge carriers, remains a significant area of research. The study demonstrates recent developments in high-value carbon-based photocatalysts synthesis from various waste precursors, including zoonotic, phytogenic, polyolefinic, electronic, and biomedical, highlighting the progression as photocatalysts and adsorbents for wastewater treatment and water splitting applications. This review highpoints the benefits of using waste as a precursor to support sustainability and circular economy and the risks associated with their use. Finally, we support that a sustainable society will eventually be realized by exploring present obstacles and potential steps for creating superior carbon-based nanomaterials in the future.

Chemical safety using functionalized carbon nanomaterials: neutralization and detection of organophosphorus compounds

Functionalized carbon nanomaterials for dealing with organophosphates.

Enhanced energy delivery of direct-write fabricated reactive materials with energetic graphene oxide

Aluminum (Al) based reactive materials are of interest as their addition can significantly increase the energy density of energetic composites such as solid propellants. In this study, we employed graphene oxide (GO) as an energetic gas generator to increase the ignitability of Al and promote the flame propagation of Al/CuO thermite composites. Compared to the pristine Al/CuO composite, 2.5 wt % addition of GO releases gas and heat upon disproportionation, resulting in a 2X higher burn rate and heat flux. Though both GO and reduced graphene oxide (rGO) addition can reduce the agglomeration size of Al NPs by 2X, GO is more energetic with heat and gas release at low temperature, granting it the ability to increase the ignitability of Al NPs and promote the energy delivery of Al/CuO composite. This study provides a simple way to increase the energy delivery rate of reactive materials by adding a small percentage of functionalized carbon nanomaterials.

Recent Progress on Carbon‐Based Electrocatalysts for Oxygen Reduction Reaction: Insights on the Type of Synthesis Protocols, Performances and Outlook Mechanisms

AbstractDue to their low cost, accessibility of resources, and improved stability and durability, carbon‐based nanomaterials have attracted significant attention as cathode materials for oxygen reduction reactions. These materials also exhibit intrinsic physical and electrochemical features. However, their potential for use in fuel cells is constrained by low ORR activity and slow kinetics. Carbon nanomaterials can be functionalized and doped with heteroatoms to change their morphologies and generate a large number of oxygen reduction active sites to lessen the problems. Doping the carbon lattice with heteroatoms like N, S, and P and functionalizing the carbon structure with −OCH3, −F, −COO−, −O− are two of these modifications that can change specific properties of the carbon nanomaterials like expanding interlayer distance, producing a large number of active sites, and enhancing oxygen reduction activity. When compared to pristine carbon‐based nanomaterials, these doped and functionalized carbon nanomaterials, including their composites, exhibit accelerated rate performance, outstanding stability, and higher methanol tolerance. This article summarizes the most recent developments in heteroatom‐doped and functionalized carbon‐based nanomaterials, covering different synthesis approaches, characterization methods, electrochemical performance, and oxygen reduction reaction mechanisms. As cathode materials for fuel cell technologies, the significance of heteroatom co‐doping and transition metal heteroatom co‐doping is also underlined.

P-Type Functionalized Carbon Nanohorns and Nanotubes in Perovskite Solar Cells.

The incorporation of p-type functionalized carbon nanohorns (CNHs) in perovskite solar cells (PSCs) and their comparison with p-type functionalized single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) are reported in this study for the first time. These p-type functionalized carbon nanomaterial (CNM) derivatives were successfully synthesized by [2 + 1] cycloaddition reaction with nitrenes formed from triphenylamine (TPA) and 9-phenyl carbazole (Cz)-based azides, yielding CNHs-TPA, CNHs-Cz, SWCNTs-Cz, SWCNTs-TPA, DWCNTs-TPA, and DWCNTs-Cz. These six novel CNMs were incorporated into the spiro-OMeTAD-based hole transport layer (HTL) to evaluate their impact on regular mesoporous PSCs. The photovoltaic results indicate that all p-type functionalized CNMs significantly improve the power conversion efficiency (PCE), mainly by enhancing the short-circuit current density (Jsc) and fill factor (FF). TPA-functionalized derivatives increased the PCE by 12-17% compared to the control device without CNMs, while Cz-functionalized derivatives resulted in a PCE increase of 4-8%. Devices prepared with p-type functionalized CNHs exhibited a slightly better PCE compared with those based on SWCNTs and DWCNTs derivatives. The increase in hole mobility of spiro-OMeTAD, additional p-type doping, better energy alignment with the perovskite layer, and enhanced morphology and contact interface play important roles in enhancing the performance of the device. Furthermore, the incorporation of p-type functionalized CNMs into the spiro-OMeTAD layer increased device stability by improving the hydrophobicity of the layer and enhancing the hole transport across the MAPI/spiro-OMeTAD interface. After 28 days under ambient conditions and darkness, TPA-functionalized CNMs maintained the performance of the device by over 90%, while Cz-functionalized CNMs preserved it between 75 and 85%.

(Invited) Carbon Nano-Onions: Potassium Intercalation and Reductive Covalent Functionalization

Functionalization of carbon nanomaterials is a promising approach to controllably engineer the band gap structure, create novel architectures, and manipulate the interfacial characteristics of graphene and carbon nanotubes, increasing their processability.[1,2] Herein we report the synthesis of covalently functionalized carbon nano-onions (CNOs) via a reductive approach using unprecedented alkali-metal CNO intercalation compounds. For the first time, an in situ Raman study of the controlled intercalation process with potassium has been carried out revealing a Fano resonance in highly doped CNOs. The intercalation was further confirmed by electron energy loss spectroscopy and X-ray diffraction. Moreover, the experimental results have been rationalized with DFT calculations. Covalently functionalized CNO derivatives were synthesized by using phenyl iodide and n-hexyl iodide as electrophiles in model nucleophilic substitution reactions. The functionalized CNOs were exhaustively characterized by statistical Raman spectroscopy, thermogravimetric analysis coupled with gas chromatography and mass spectrometry, dynamic light scattering, UV–vis, and ATR-FTIR spectroscopies. This work provides important insights into the understanding of the basic principles of reductive CNOs functionalization and will pave the way for the use of CNOs in a wide range of potential applications, such as energy storage, photovoltaics, or molecular electronics.[3] [1] Abellán, G.; Schirowski, M.; Edelthalhammer, K. F.; Fickert, M.; Werbach, K.; Peterlik, H.; Hauke, F.; Hirsch, A. J. Am. Chem. Soc. 2017, 139, 5175.[2] Schirowski, M.; Abellán, G.; Nuin, E.; Pampel, J.; Dolle, C.; Wedler, V.; Fellinger, T. P.; Spiecker, E.; Hauke, F.; Hirsch, A. J. Am. Chem. Soc. 2018, 140, 3352.[3] M. E. Pérez-Ojeda, E. Castro, C. Kröckel, M. A. Lucherelli, U. Ludacka, J. Kotakoski, K. Werbach, H. Peterlik, M. Melle-Franco, J. C. Chacón-Torres, F. Hauke, L. Echegoyen, A. Hirsch, G. Abellán, J. Am. Chem. Soc. 2021, 143, 18997. Figure 1

Immobilization of iron phthalocyanine on MOF-derived N-doped carbon for promoting oxygen reduction in zinc-air battery

Functional carbon nanomaterials play a crucial role in the cathodic oxygen reduction reaction (ORR) for sustainable fuel cells and metal-air batteries. In this study, we propose an effective approach to immobilize iron phthalocyanines (FePc) by employing a porous N-doped carbon material, denoted as NC-1000, derived from a sheet-shaped coordination polymer. The resulting NC-1000 possesses substantial porosity and abundant pore defects. The nitrogen sites within NC-1000 not only facilitate FePc adsorption but also optimize the electron distribution at the Fe-N site.The FePc@NC-1000 composite material exhibits a significant number of active centers in the form of Fe-N4 moieties, showcasing satisfactory ORR activity. Specifically, it demonstrates an onset potential of 0.99 V, a positive half-wave potential of 0.86 V, a large limiting current of 5.96 mA cm−2, and a small Tafel slope of 44.41 mV dec-1. Additionally, theoretical calculations and experimental results confirm the favorable performance and durability of zinc-air batteries assembled using FePc@NC-1000, thereby highlighting their considerable potential for practical applications. Overall, this study provides a comprehensive exploration of the enhanced catalytic performance and increased stability of metal–organic framework-derived functional carbon nanomaterials as cost-effective, efficient, and stable catalysts for the ORR.

Comparative study of physico‐mechanical performance of PPC mortar incorporated 1D/2D functionalized nanomaterials

AbstractThe current study investigates the effect of adding graphene oxide (GO) and functionalized multiwalled carbon nanotubes (FMWCNTs) in pozzolana Portland cement (PPC) mortars to evaluate their mechanical and electrical resistivity properties. The effects of 1D and 2D functionalized carbon nanomaterials in PPC have been studied. At 90 days of curing, the g1PPC (.0015% of GO by weight percentage of binder) and c1PPC (.0015% of FMWCNTs by weight percentage of binder) showed a significant improvement in the physico‐mechanical performance of the pozzolana Portland cement composited (PPCC) mortars. The enhanced compressive strength was found to be 11.67% and 8.74% for g1PPC and c1PPC, respectively, as compared to the control specimen (PPC‐C). The increased tensile splitting strength was observed to be 26.39% and 20.61% for g1PPC and c1PPC, respectively, as compared to PPC‐C. The electrical resistivity of PPCC mortars have been shown a significant improvement for g1PPC and c1PPC. This might be due to the densification of calcium silicate hydrate (C–S–H) gel and hydration products. Powdered X‐ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT‐IR). Field emission‐scanning electron microscope (FE‐SEM) was able to support the improved strength of PPCC mortars via formation of ettringite and needle‐shaped crystals in hydrated products.

Development of the New Sensor Based on Functionalized Carbon Nanomaterials for Promethazine Hydrochloride Determination

Promethazine hydrochloride (PM) is a widely used drug so its determination is important. Solid-contact potentiometric sensors could be an appropriate solution for that purpose due to their analytical properties. The aim of this research was to develop solid-contact sensor for potentiometric determination of PM. It had a liquid membrane containing hybrid sensing material based on functionalized carbon nanomaterials and PM ions. The membrane composition for the new PM sensor was optimized by varying different membrane plasticizers and the content of the sensing material. The plasticizer was selected based on calculations of Hansen solubility parameters (HSP) and experimental data. The best analytical performances were obtained using a sensor with 2-nitrophenyl phenyl ether (NPPE) as the plasticizer and 4% of the sensing material. It had a Nernstian slope (59.4 mV/decade of activity), a wide working range (6.2 × 10-7 M-5.0 × 10-3 M), a low limit of detection (1.5 × 10-7 M), fast response time (6 s), low signal drift (-1.2 mV/h), and good selectivity. The working pH range of the sensor was between 2 and 7. The new PM sensor was successfully used for accurate PM determination in a pure aqueous PM solution and pharmaceutical products. For that purpose, the Gran method and potentiometric titration were used.

Graphitization by Metal Particles.

Graphitization of carbon offers a promising route to upcycle waste biomass and plastics into functional carbon nanomaterials for a range of applications including energy storage devices. One challenge to the more widespread utilization of this technology is controlling the carbon nanostructures formed. In this work, we undertake a meta-analysis of graphitization catalyzed by transition metals, examining the available electron microscopy data of carbon nanostructures and finding a correlation between different nanostructures and metal particle size. By considering a thermodynamic description of the graphitization process on transition-metal nanoparticles, we show an energy barrier exists that distinguishes between different growth mechanisms. Particles smaller than ∼25 nm in radius remain trapped within closed carbon structures, while nanoparticles larger than this become mobile and produce nanotubes and ribbons. These predictions agree closely with experimentally observed trends and should provide a framework to better understand and tailor graphitization of waste materials into functional carbon nanostructures.

Potentialities of fluorescent carbon nanomaterials as sensor for food analysis.

Food safety and quality are among the most significant and prevalent research areas worldwide. The fabrication of appropriate technical procedures or devices for the recognition of hazardous features in foods is essential to safeguard food materials. In the recent era, developing high-performance sensors based on carbon nanomaterial for food safety investigation has made noteworthy progress. Hence this review briefly highlights the different detection approaches (colorimetric sensor, fluorescence sensor, surface-enhanced Raman scattering, surface plasmon resonance, chemiluminescence, and electroluminescence), functional carbon nanomaterials with various dimensions (quantum dots, graphene quantum dots) and detection mechanisms. Further, this review emphasizes the assimilation of carbon nanomaterials with optical sensors to identify multiple contaminants in food products. The insights of carbon-based nanomaterials optical sensors for pesticides and insecticides, toxic metals, antibiotics, microorganisms, and mycotoxins detection are described in detail. Finally, the opportunities and future perspectives of nanomaterials-based optical analytical approaches for detecting various food contaminants are discussed.

Hydrogels Based on Polyacrylamide and Functionalized Carbon Nanomaterials for Adsorption of a Cationic Dye

Malachite green (MG) is used for the dyeing of cotton, paper, and jute, among other materials, and presents acute toxicity to a wide range of aquatic and terrestrial animals. A polyacrylamide (PA) hydrogel modified with a low content of oxygenated and aminated carbon nanomaterials may be a suitable candidate to adsorb MG from wastewater. Herein, graphene oxide and carbon nanotubes (CNTs) were incorporated during the in situ polymerization of PA. The hydrogels were characterized through thermogravimetry, differential scanning calorimetry and infrared spectroscopy as well as imagined by scanning electron microscopy. The swelling and adsorption capacity were investigated to explore the influences of different carbon dimensionalities (1D and 2D), zeta potentials and nanofiller concentrations on the adsorption behavior of the hydrogel. There was an increase of approximately 1500% in the adsorption capacity after 24 h of exposure of a hydrogel with graphene oxide (GO) at 0.25 wt% with respect to the neat PA. Aminated graphene produced similar gains in the adsorption capacity of the GO-hydrogel, although it presents a positive zeta potential that is the opposite of that of GO. The modified CNTs showed smaller gains in the adsorption capacity, reaching a maximum 400% increase with respect to the PA hydrogel. The main factors that seem to affect the adsorption capacity were the dimensionality and degree of functionalization. The graphene oxide-based nanofillers were 3 to 4 times more functionalized than the nanotubes. The adsorption results were adjusted with a pseudo-second order kinetic model that allowed a complementary discussion about the nature of the physico-chemical effects on the process of MG adsorption in the hydrogel nanocomposites.

Effects of Carbon Nanomaterials and Aloe vera on Melanomas-Where Are We? Recent Updates.

Melanoma is an aggressive skin cancer that affects approximately 140,000 people worldwide each year, with a high fatality rate. Available treatment modalities show limited efficacy in more severe cases. Hence, the search for new treatment modalities, including immunotherapies, for curing, mitigating, and/or preventing cancer is important and urgently needed. Carbon nanoparticles associated with some plant materials, such as Aloe vera, have shown appealing antineoplastic activity, derived mainly from the compounds aloin, aloe-emodin, barbaloin acemannan, and octapeptide, thus representing new possibilities as antitumor agents. This systematic review aims to arouse interest and present the possibilities of using Aloe vera combined with carbon-based nanomaterials as an antineoplastic agent in the treatment and prevention of melanoma. Limitations and advances in melanoma treatment using functionalized carbon nanomaterials are discussed here. Moreover, this review provides the basis for further studies designed to fully explore the potential of carbon nanomaterials associated with Aloe vera in the treatment of various cancers, with a focus on melanoma.

Polyoxometalates-graphene nanocomposites modified electrode for electro-sensing detection of Sudan I in food

Sudan I, a lipophilic azo dye -dye, is desirable and urgent to be accurate detected due to its increasing levels and high toxicity in food and environmental monitoring and analysis. Herein, a sensitive electrochemical sensor for Sudan I was established based on a new K10P2W18Fe4(H2O)2O68 functionalized carbon nanomaterials (Fe4P2W18-GNPS). The electrode modified nanocomposite, Fe4P2W18-GNPS, was successfully fabricated and characterized by FTIR, SEM and UV–vis. The effective combination of Fe4P2W18 and graphene exhibited high electrocatalytic activity towards the oxidation of Sudan I, promote charge transfer, and more sensing sites. Under optimized experimental conditions, the proposed differential pulse voltammetry (DPV) showed excellent analytical performances for Sudan I with the limit of detection (LOD) of 5 nM (S/N = 3), the sensitivity of 13.10 μA·μM−1cm−2 at the 0.005–2 μM and 0.39 μA·μM−1cm−2 at 10–200 μM. The stability and reproducibility make the electrochemical sensor suitable for detecting the Sudan I in food.

Water purification from chlorobenzenes using heteroatom-functionalized carbon nanofibers produced on self-organizing Ni-Pd catalyst

The development of effective methods for the processing of hazardous wastes containing chlorinated hydrocarbons still remains a big challenge. Herein, the approach allowing the transformation of chlorohydrocarbons into functionalized carbon nanomaterials was demonstrated for 1,2-dichloroethane (DCE) used as a model compound. Carbon nanofibers (CNF) doped with nitrogen and oxygen heteroatoms were fabricated by a joint decomposition of DCE and co-reagent (CH3CN, NH4OH, C2H5OH, and H2O). The Ni-Pd (5%) alloy was used as a catalyst precursor for the CNF synthesis. Pristine Ni-Pd alloy was found to undergo disintegration under the reaction conditions and to induce an active growth of the functionalized carbon nanofibers. The obtained CNF were shown to have a similar segmental structure of carbon filaments and to possess high specific surface area (up to 470 m2/g) and porosity (up to 0.9 cm3/g). According to X-ray photoelectron spectroscopy data, the nitrogen content within CNF samples prepared using N-comprising precursors was about 1.0–1.7 at%. The total oxygen content reaches 3.6 at%. The obtained materials were demonstrated to be attractive for the dichlorobenzene adsorption from its aqueous solutions.

Critical Optimization of Phosphorus Functionalized Carbon Nanomaterials for Metal‐Free Solar Hydrogen Production and Simultaneous Organic Transformation

AbstractComplete metal‐free P‐functionalized carbon nanomaterials are synthesized from a single molecular precursor, phytic acid, for photocatalytic solar H2 production and simultaneous organic transformation of 4‐methyl benzyl alcohol to 4‐methyl benzaldehyde by managing the complete redox cycle. It is observed that by increasing the carbonization time, P‐functionalized amorphous carbon dots convert to the highly defined 2D sheet‐like nanostructure with optimum P‐functionality, resulting in efficient light absorption, charge separation, and improved active sites for photocatalysis. Finally, the highly defined sheet‐like structure converts to a more defected aggregated form, resulting in the depletion of photocatalytic efficiency. The structural and elemental features are further correlated with the ongoing photophysics by means of steady‐state and time‐resolved fluorescence spectroscopy. Transient photocurrent responses and Mott‐Schottky plots directly support the optimization of P‐functionalized carbon nanostructure for efficient photocatalysis. Finally, the detailed computational studies are carried out to unveil the charge separation mechanism and the crucial role of P‐functionalities as active sites for better charge accumulation as well as H2O adsorption on the surface. Overall, the in‐depth structure–property correlation and critical optimization of the heteroatom functionalized carbon nanomaterials will open up new possibilities for further development of metal‐free photocatalysts for solar‐energy conversion devices.