Carbon Nitride Nanotubes Research Articles

Template Directed Synthesis of Boron Carbon Nitride Nanotubes (BCN‐NTs) and Their Evaluation for Energy Storage Properties

AbstractA unique approach has been applied for the synthesis of 1D boron carbon nitride nanotubes (BCN‐NTs) using MnO2 nanowires as templates. BCN‐NTs have been evaluated in Na‐ion batteries, Li‐ion batteries, and supercapacitors as electrode material and exhibited excellent and stable electrochemical performance. BCN‐NTs as an anode for Na‐ion battery has been shown to be highly stable up to 3000 cycles with capacity retention of 95 mAh g−1, at a high current density of 1 A g−1. In the case of the Li‐ion battery, these BCN‐NTs show a specific capacity of 563 mAh g−1 at a current density of 50 mA g−1. Finally, when used as an electrode for a supercapacitor, BCN‐NTs display a specific capacity of 221 F g−1 at a current density of 3 A g−1 and 168 F g−1 even at a very high current density of 30 A g−1 exemplifying the excellent rate performance. The multifunctionality and stable performance of BCN‐NTs among various electrochemical energy storage systems highlight the robustness of the material and make it an excellent candidate for scalable production and commercialization.

Nanoarchitectonics of Ag-modified g-C3N4@halloysite nanotubes by a green method for enhanced photocatalytic efficiency

In this study, a facile and cost effective green synthesis has been utilized for the synthesis of silver nanoparticles (Ag-NPs)–modified graphitic carbon nitride (Ag-g-C3N4) and halloysite nanotubes (HNTs) using Centella Asiatica (L.) extract, urea and mineral source of natural halloysite (HNTs), respectively. Here, silver ions (Ag+) were reduced to Ag-NPs using an aqueous Centella Asiatica (L.) as reducing and capping agent. The synthesized Ag-g-C3N4@HNTs were characterized by various physiochemical methods such as XRD, FT-IR, BET, SEM, TEM, EDS–mapping, UV–vis-DRS, PL, XPS and EPR methods. In the photocatalytic experiment, Ag-g-C3N4@HNTs nanocomposite with silver surface plasmon resonance of Ag-NPs and multi-layer hollow nanotubes was outperformed by the individual components. With an in-depth study on the photocatalytic mechanisms, we can conclude that the enhanced performance of the nanocomposite is due to the effective separation of photogenerated electrons and superoxide radicals (•O2–) in water molecules. The photocatalyst preserved excellent photostability for up to four cycles (with a minor activity reduction from 95% to 91%). These results demonstrated the development of novel semiconductors from inexpensive resources with effective photoactivity to mitigate environmental problems.

Porous carbon nitride nanotubes efficiently promote two-electron O2 reduction for photocatalytic H2O2 production

Supramolecular self-assembly was used to synthesize uniform porous carbon nitride nanotubes successfully. The large specific surface area and superior electron transport performance are provided by nanotube structures. The temperature programmed desorption (TPD) test and the density functional theory (DFT) calculation indicate that porous carbon nitride nanotubes show a significant adsorption of O2. At the same time, the rotating ring-disk electrode (RRDE) experiments demonstrate that the porous carbon nitride nanotubes improved the selectivity of 2e- oxygen reduction reaction (ORR) (60% vs. 90%, 0.3 V vs. RHE) greatly. Consequently, the yield of H2O2 by porous carbon nitride nanotubes (93.89 μmol/L) is 2.4 times more than that of the original carbon nitride. Therefore, this research provides a feasible strategy for designing photocatalytic materials with high 2e- ORR selectivity.

Efficient photocatalytic remediation of typical antibiotics in water via Mn3O4 decorated carbon nitride nanotube

Antibiotic abuse will seriously affect the ecology and environment. Photocatalytic oxidation technology based on carbon nitride (g-C3N4) has been widely adopted to treat wastewater containing antibiotics. Here, a novel composite photocatalyst MCNT was prepared by loading manganese oxide (Mn3O4) on the surface of g-C3N4 nanotubes (CNT). Three typical antibiotics, trimethoprim (TMP), norfloxacin (NOR), and tetracycline (TC) were used as model contaminants to evaluate the oxidative properties of prepared materials. Compared with bulk g-C3N4, the degradation rates of TMP, NOR, and TC catalyzed by MCNT-5 were increased by 2, 3, and 1.4 times, respectively, mainly due to 1) the larger specific surface area of the nanotube structure of CNT, which provides abundant active sites for antibiotic adsorption and catalytic oxidation, and 2) the loading of Mn3O4, which promotes the directional migration of photogenerated charges and improves the separation efficiency of photogenerated electrons and holes. The free radical capture and quenching experiments confirmed that MCNT degraded the target organic pollutants with hydroxyl radical (·OH) and singlet oxygen (1O2) as the main active oxidants. This catalyst maintained 80% photocatalytic oxidation performance after five cyclic experiments. This study provides new insights into developing efficient, stable, and environmentally-friendly photocatalysts and provides a new dimension to mitigate the antibiotic pollution problem.

Formation of ionic carbon nitride towards an environmentally friendly synthesis of 2-amino-5-alkylidene-thiazol-4-one

Graphitic carbon nitride (g-C3N4) has a layered structure similar to graphite and presents exciting and unique support in organic transformations. Using the edge-functionalized graphitic carbon nitride by doping it with various functional groups and transforming it into another morphology has become the center of attention in the recent decade. It has a nitrogen-rich structure with weak base properties; therefore, it must improve its properties with various functionalization. Herein, for the first time, template-free ionic carbon nitride nanotubes (K-g-C3N4) were created via thermal polymerizing and aqueous alkaline liquid-phase exfoliation. The characterization of alkaline K-doped ionic graphitic carbon nitride (K-g-C3N4) was determined by FT-IR, SEM, EDS, and TGA analysis.A simple, facile, and efficient synthesis of 2-amino-5-alkylidene-thiazol-4-ones derivatives via a multicomponent reaction of various aldehyde, amines, and rhodanine in ethanol using a reusable K-g-C3N4 as a green catalyst has been developed. The reaction scope was explored by varying the structures of aldehydes and amines with rhodamine. Various 2-amino-5-alkylidene-thiazol-4-ones were established in yields ranging between 65 and 96% for 60–180 min. Due to the heterogeneous nature of K-g-C3N4, the catalyst could be recovered by centrifugation and reused in five cycles without a decrease in catalytic activity. Operational simplicity, facile fabricable catalyst, broad substrate scope, readily available starting materials, nontoxic, highly stable, environment-friendly catalyst and solvent, suitable to excellent yields, and simple work-up are the prominent features of this methodology.

A Unique, Porous C3N4 Nanotube for Electrochemiluminescence with High Emission Intensity and Long-Term Stability: The Role of Calcination Atmosphere.

Developing excellent strategies to optimize the electrochemiluminescence (ECL) performance of C3N4 materials remains a challenge due to the electrode passivation, causing weak and unstable light emission. A strategy of controlling the calcination atmosphere was proposed to improve the ECL performance of C3N4 nanotubes. Interestingly, we found that calcination atmosphere played a key role in specific surface area, pore-size and crystallinity of C3N4 nanotubes. The C3N4 nanotubes prepared in the Air atmosphere (C3N4 NT-Air) possess a larger specific surface area, smaller pore-size and better crystallinity, which is crucial to improve ECL properties. Therefore, more C3N4•− excitons could be produced on C3N4 NT-Air, reacting with the SO4•− during the electrochemical reaction, which can greatly increase the ECL signal. Furthermore, when C3N4 nanotube/K2S2O8 system is proposed as a sensing platform, it offers a high sensitivity, and good selectivity for the detection of Cu2+, with a wide linear range of 0.25 nM~1000 nM and a low detection limit of 0.08 nM.

Supramolecular Polymer Intertwined Free-Standing Bifunctional Membrane Catalysts for All-Temperature Flexible Zn–Air Batteries

HighlightsRational design of 3D flexible free-standing membrane catalysts with protonation between supramolecular polymers and nitrogen-deficient carbon nitride nanotubes frameworks via facile bottom-up self-conversion approach.PEMAC@NDCN demonstrates the lowest reversible oxygen bifunctional activity of 0.61 V with exceptional long-lasting durability, surpassing the commercial and reported champion oxygen catalysts.Engineering catalytically active cathode materials enabled all-temperature flexible Zn–air batteries with high electrochemical and mechanical performances (temperature of − 40 to 70 °C) under harsh operations.

O, S-g-C3N4 nanotubes as photovoltaic boosters in quantum dot-sensitized all-weather solar cells: a synergistic approach for enhanced power conversion efficiency in dark-light conditions

All up-to-the-minute solar cells generate highly efficient electricity under sunlight. However, the power outputs are ∼ zero under dark conditions due to the relatively low visible light intensity. We report high-performance quantum dots-sanitized all-weather solar cells (QDSSCs). The devices were based on rationally designed carbon quantum dots (CQDs) decorated oxygen and sulfur co-doped graphitic carbon nitride nanotubes (O, S-g-C3N4 NTs)-sensitized TiO2/long-persistence phosphor (LPP) photoanodes and Pt counter electrodes (CE). O, S-doped-g-C3N4 NTs can act as photo-boosters as well as the blocking layer to prevent the backflow of photoexcited electrons and prevent their recombination with the electrolyte. LPPs can store unabsorbed light ranging from visible to infrared light across the photoanode and convert it into green fluorescence, ultimately persistent CQDs/O, S-g-C3N4 NTs irradiation, and electricity generation under sunlight illumination in all light-dark environments. The maximum PCE was 18.5% for the device 7-CC/L prepared with a composite of CQDs and O, S-g-C3N4 NTs with an optimized weight of 7 mg and 0.2 g, respectively.

New highly efficient 2D/1D HAp/g‒C3N4 photocatalyst thin film insight into crystal orientation and C‒vacancy effects.

The novel synthetic Sol‒EPD process of a thin film including of well decorated g‒C3N4 nanotubes on plate‒like hydroxyapatite (HAp) were applied. Using Sol‒EPD designable method anisotropic growth of HAp nanocrystals on the substrate were achieved. It has provided the orientation of the different crystal facets resulted in the photogenerated O‒vacancy from phosphate groups. Based on the studied XRD pattern, EPD deposited film of HAp was oriented along c‒plane that can improve the photocatalytic activity of the designed composited film. Systematic designing was applied for decoration of g‒C3N4 nanotubes on the HAp under thermal condensation of melamine coincide with calcination of HAp. This new designed HAp/g‒C3N4 nanofilm was shown high photocatalytic efficiency and completely degradation of persistent pollutant of 4‒nitrophenol in the aqueous solution. According to the electrochemical impedance spectroscopy and current density studies, the higher charge separation/low charge recombination results were obtained for composited g‒C3N4/HAp nano‒film comparing with the single films of HAp and urchin like g‒C3N4. This high separation of charge pairs should be also assigned to the special designed morphology. In addition, wrapped like structure of g‒C3N4 nanotubes with C‒vacancy around HAp nanoplates play key role in separation of photo‒induced charge pairs, light diffusion, and high light harvesting within hollow nanotube. It can be highlighted that the composite degraded more than 95% of 4‒nitrophenol during 90min that after 5 runs the photocatalytic activity was not significantly changed.

Carbon vacancies enriched carbon nitride nanotubes for Pd coordination environment optimization: Highly efficient photocatalytic hydrodechlorination and CO2 cycloaddition

The use of easily available solar energy to achieve pollutants efficient degradation and waste carbon resource CO2 utilization under mild conditions is highly desired. Herein, novel carbon vacancies enriched nanotubes graphitic carbon nitride (SCNT-500) has been successfully fabricated via melamine (MA) supramolecular hydrogen-bonded self-assembly in the presence of H2SO4. Pd NPs loaded carbon vacancies enriched carbon nitride nanotubes (Pd/SCNT-500) were used for photocatalytic chlorophenols hydrodechlorination and CO2 cycloaddition with styrene oxide. Up to 6.93 s-1 4-chlorophenol hydrodechlorination TOF and obviously improved CO2 cycloaddition efficiency could be realized with Pd/SCNT-500. The improved photocatalytic efficiency should be related to the morphology and carbon vacancies based Pd coordination environment optimization. Such as, the surface area increased nanotubes structure promoted light harvesting along with photoelectrons and holes generation; the carbon vacancies improved excited electrons capture, photoinduced carriers recombination inhibition along with substrates adsorption with electron rich Pd NPs. Mechanism studies not only demonstrated the important role of atomic hydrogen and Pd coordination environment optimization in the chlorophenols hydrodechlorination, but also confirmed the promotion ability of photogenerated electrons on CO2 cycloaddition.

A comparative study on the interfacial characteristics and tensile behaviors of natural rubber composites reinforced by carbon and boron nitride nanotubes

AbstractThe reinforcing effect of carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs) on the interfacial characteristics and tensile behaviors of natural rubber (NR) composites were comparatively investigated using molecular dynamics simulations. A pull‐out simulation was performed to study the interfacial characteristics between CNTs, BNNTs and NR matrices. The results showed that increases of about 56.63% and 90.14% in the interfacial frictional force and interfacial shear strength were obtained for the composites by the incorporation of BNNTs than those by the incorporation of CNTs. A uniaxial tensile process was fulfilled by using the constant true strain rate method to study the mechanical properties of the NR composites reinforced by CNTs and BNNTs. The results indicated that significant increases of 22.34% and 26.59% in the Young's modulus, 4.34% and 19.28% in the yield stress, and 11.07% and 8.01% in the tensile strength were respectively achieved by the incorporation of CNTs and BNNTs as reinforcements. To deeply reveal the deformation mechanisms of the NR composites, the mean square displacement and root‐mean‐square radius of gyration of the NR chains, the fractional free volume in the NR composites, and the interfacial interaction energy were calculated and discussed accordingly.

Adsorption of thiotepa anticancer drugs on the C3N nanotube as promising nanocarriers for drug delivery.

This paper focused on the efficiency of carbon nitride nanotubes functionalized with alanine amino acid (f-C3NNTs) in thiotepa (TPA) anti-cancerous drug delivery via density functional theory (DFT). Pristine C3NNTs were incorporated for comparison. TPA was found to spontaneously undergo exothermic adsorption onto the nanostructures. The f-C3NNT/TPA complexes showed the highest interaction strength. The adsorption distance of TPA was found to be smaller, with a greater adsorption capacity and solubility on the f-C3NNT surface than on the pristine C3NNT surface. As they were polar, all the complexes were concluded to be insoluble within an aqueous phase. The quantum molecular descriptors revealed the f-C3NNT nanocarriers to be more reactive than the C3NNT carrier. The drug was found to spontaneously and exothermically interact with f-C3NNT. As a result, f-C3NNT would be promising for TPA adsorption in drug delivery applications.

Molybdenum atomic sites embedded 1D carbon nitride nanotubes as highly efficient bifunctional photocatalyst for tetracycline degradation and hydrogen evolution

Metal single atom catalysts (MSACs) stabilized by nitrogen in carbon nitride are intriguing photocatalysts for energy and environmental applications. However, the synergistic effect of simultaneously tailoring the carbon nitride nanostructure and fabricating single metal atoms has not been explored for photocatalysis. Herein, we report the facile synthesis of Mo atomic sites on porous carbon nitride nanotubes (Mo1@CNNTs) obtained by template free polymerization of urea and melamine monomers. AC-HAADF-STEM image confirmed the existence of isolated Mo atoms, while XAS analysis revealed the formation of unique atomic Mo-N3 structures on CNNTs. Incorporation of Mo atomic sites into CNNTs modulated electronic and band structure and thus improved light harvesting, charge separation, and transfer. The synergy of 1D nanotube structure and distinct atomic Mo sites turned Mo1@CNNTs as a highly efficient bifunctional photocatalyst for hydrogen evolution and tetracycline degradation. On one side Mo1@CNNTs demonstrated hydrogen evolution rate of 4861 µmol.h−1.g−1, while on the other hand Mo1@CNNTs achieved 97.3% TC degradation under visible light irradiation. DFT investigations revealed that induction of unique Mo atomic sites not only tuned the electronic structure of CNNTs, but also localized photoexcited electrons around Mo atoms to activate O2(ads) and generate reactive species (.O2–/.OH) for TC degradation. We believe that our findings are promising and will open new opportunities for the design of novel photocatalyst for a sustainable future.

Novel and efficient strategy for chlorophenols and CO2 transformation over carbon nitride nanotubes: Effect of the hydroxyl grafting and surface electron polarization

Herein, novel, green and efficient strategy was developed for environmental pollutant chlorophenols and carbon dioxide transformation to carboxylic acids containing fine chemicals over carbon nitride (C3N4) nanotubes based photocatalysis. C3N4 nanotubes structure with hydrothermal treatment method provided the increased active sites, enhanced light absorption capacity and improved charge transfer efficiency. C3N4 nanotubes further modified by hydroxyl groups in situ grafting and halogen ions were prepared by simple hydrothermal treatment strategy with ammonium salt and potassium iodide. Owing to the photogenerated holes capture improvement, hydroxyl groups in situ grafting policy obviously enhanced the chlorophenols and CO2 transformation. Moreover, the chlorophenols carboxylation efficiency was further promoted with the synergistic effect of hydroxyl groups assisted photogenerated holes capture and halogen ions induced surface polarization.

Thermal conductivities of hydrogen encapsulated boron nitride and hybrid boron nitride – carbon nanotubes using molecular dynamics simulations

In this work, we investigated the thermal conductivities of boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) as potential hydrogen storage materials using atomistic nonequilibrium molecular dynamics (NEMD) simulations. Pristine and defective (containing B/N/C single atom vacancy or B-N double atom vacancies) capped armchair BNNTs and BN-C heteronanotubes have been studied. Furthermore, thermal conduction in BNNT, CNT, and BN(50%)-C(50%) heteronanotubes with varying amounts of encapsulated H2 molecules has been evaluated. We compare the performance of the reactive forcefield ReaxFF with non-reactive Tersoff-adaptive intermolecular reactive empirical bond order (AIREBO)-Lennard-Jones (TALJ) potentials combination. The ReaxFF potential yielded consistently lower thermal conductivity (k) for all the nanotubes. However, it provides a better qualitative prediction of thermal transport in the nanotubes (in terms of k reduction due to defects and entrapped H2, and sensitivity to composition as reflected in the phonon density of states) whereas Tersoff/TALJ potentials provide a better quantitative prediction of k while failing to account for acoustic phonon details. Near-linear mixing rule for k across the CNT-BNNT composition suggested by both potentials indicates smooth interfacial heat transport at the heterojunctions.

Water Flow in Single-Wall Nanotubes: Oxygen Makes It Slip, Hydrogen Makes It Stick.

Experimental measurements have reported ultrafast and radius-dependent water transport in carbon nanotubes which are absent in boron nitride nanotubes. Despite considerable effort, the origin of this contrasting (and fascinating) behavior is not understood. Here, with the aid of machine learning-based molecular dynamics simulations that deliver first-principles accuracy, we investigate water transport in single-wall carbon and boron nitride nanotubes. Our simulations reveal a large, radius-dependent hydrodynamic slippage on both materials, with water experiencing indeed a ≈5 times lower friction on carbon surfaces compared to boron nitride. Analysis of the diffusion mechanisms across the two materials reveals that the fast water transport on carbon is governed by facile oxygen motion, whereas the higher friction on boron nitride arises from specific hydrogen–nitrogen interactions. This work not only delivers a clear reference of quantum mechanical accuracy for water flow in single-wall nanotubes but also provides detailed mechanistic insight into its radius and material dependence for future technological application.

Synthesis of MoS2 nanotube using a sacrificial template method as advanced anode material for lithium-ion batteries

Molybdenum disulfide (MoS 2 ) is a promising anode material in lithium ion batterys (LIBs). However, poor conductivity and stability severely hinder its application. Herein, carbon nitride nanotubes are used as template to in-situ grow ultrathin MoS 2 nanosheets and after removing carbon nitride nanotubes, MoS 2 nanosheets with an uniform tube-like structure can be obtained. Benefiting from hollow structure with long aspect ratio and well-dispersed ultrathin MoS 2 layers, the obtained MoS 2 nanotubes favor mass diffusion, shorten ion transfer distance and can effectively alleviate volume expansion. The obtained MoS 2 nanotubes deliver a reversible capacity of 1112.3 mAh g −1 (0.5 A g −1 after 500 cycles), a good long cycling life (428 mAh g −1 at 2 A g −1 after 1000 cycles). For the MoS 2 -NT//LiCoO 2 full cell, it exhibits stable cycling performance with discharge capacity of 143 mAh g −1 at 0.1 A g −1 after 100 cycles. The specific architecture of MoS 2 nanotubes could provide a useful design idea for the electrode of next-generation LIBs. • MoS 2 nanotube was successfully developed by a facile template method. • The nanotube structure of MoS 2 alleviates the volume changes. • MoS 2 with a high aspect ratio gives continuous electronic transmission channel. • MoS 2 nanotube exhibits an excellent cycle performance and rate capability.

Insights into the function of semi-metallic 1T’ phase ReS2 as cocatalyst decorated g-C3N4 nanotubes for enhanced photocatalytic hydrogen production activity

In this paper, the semi-metallic 1T’ phase rhenium disulfide (ReS2) nanosheets (NSs) as cocatalysts are loading on the graphitic carbon nitride (g-C3N4) nanotubes (NTs) for photocatalytic hydrogen (H2) production. The as-prepared 1T′-ReS2/g-C3N4 composites present expressively enhanced photocatalytic activity. The 1T′-ReS2/g-C3N4 composite with 12 wt% 1T′-ReS2 exhibits the best photocatalytic H2 evolution performance (2275 μmol h−1 g−1), about 37 times of g-C3N4 NTs, 4 times of 2H-ReS2/g-C3N4 NTs, 6.7 times of 1T-ReS2/g-C3N4 NTs and 1.2 times of Pt/g-C3N4 NTs. Meanwhile, the apparent quantum yield (AQE) values of 1T′-ReS2/g-C3N4 (12 wt%) using 50 mg photocatalyst are 6.44% and 3.45% under light at λ = 370 nm and 456 nm, respectively. The activity tests and the DFT calculations prove that 1T′-ReS2/g-C3N4 composites have the following advantages: 1) The hollow porous g-C3N4 nanotubes are beneficial for improving the absorption and utilization of light, and the migration of photoexcited electrons; 2) After loading 1T′-ReS2 nanosheets on the g-C3N4 nanotubes, the 1T′-ReS2/g-C3N4 composites show the enhanced light absorption and fast carriers transfer, proving that the conductive 1T′-ReS2 nanosheets as cocatalysts could facilitate g-C3N4 nanotubes to generate more photoexcited charges, promote the carrier migration and separation, and supply abundant active sites for photocatalysis.

2D/1D BiOI/g-C3N4 nanotubes heterostructure for photoelectrochemical overall water splitting

To boost the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances, the BiOI/graphitic carbon nitride nanotubes (g-C3N4 nanotubes) heterojunction was synthesized herein through the hydrothermal method. BiOI in-situ grew on the surface of g-C3N4 nanotubes derived from melamine. The rapid recombination between photoexcited electrons and holes of pristine semiconductors was prevented via building the stable heterojunction. The SEM results indicated that the BiOI was wrapped around the surface of g-C3N4 nanotubes, resulting in an optimized electronic transmission pathway. Much lower charge transfer resistance at the p-n heterojunction was demonstrated compared with pristine BiOI according to the EIS results, thus leading to the faster surface reaction rates. Moreover, the composite exhibited both outstanding OER and HER activities under illuminated conditions. This study may shed light upon establishing a bifunctional photoelectrocatalysis for photoelectrochemical water splitting based on stable 2D metal and 1D metal-free nanocomposite.

Activation of Fe species on graphitic carbon nitride nanotubes for efficient photocatalytic ammonia synthesis

Photocatalytic ammonia synthesis, as a suitable alternative to traditional Haber-Bosch artificial nitrogen reduction process, has aroused widespread interest. Graphitic carbon nitride (g-C3N4) has emerged as an attractive metal-free photocatalyst, but its development in photocatalytic ammonia synthesis field is greatly shackled to the low photocatalytic activity. In this work, a highly active Fe-doped tubular graphitic carbon nitride (Fe-TCN) is reported, which demonstrates transformative performance on photosynthesis of NH3 from N2. Such excellent photocatalytic activity is derived from the incorporation of Fe species as the active sites to efficiently adsorb and activate N2 molecules on the surface of TCN. Simultaneously, surface-active Fe species are also regarded as the trap sites of electrons, and the concentrated electrons at surface-active Fe species can significantly improve the NH3 conversion efficiency. Impressively, Fe-TCN realized a 9.5-fold enhancement of NH3 production rate with the yield of 647 μmol g−1 h−1 (λ ≥ 420 nm), and the corresponding reaction pathways are also established.