Recombination Rate Of Electron Research Articles

Design and Synthesis of Sm, Y, La and Nd‐doped CeO2 with a broom‐like hierarchical structure: a photocatalyst with enhanced oxidation performance

AbstractCeO2 doped with various rare earth (RE) ions (Sm, Y, La and Nd) having a broom‐like hierarchical structure was successfully prepared by a template‐free hydrothermal method. The photooxidation performance of RE‐doped products was significantly better than that of pure CeO2, and comparative experiments showed that Sm‐doped CeO2 (SC) has superior photooxidation activity, resulting about 3.0‐times and 8.5‐times higher activities of bisphenol A (BPA) degradation and of acetaldehyde (CH3CHO) decomposition, respectively, than those of pure CeO2. Due to the incorporation of RE ions, the surface exposed cerium ions are partly substituted by those cations, resulting in a higher concentration of oxygen vacancies (Ov) in RE‐doped CeO2. The increased Ov can act as a trapping center for photo‐generated electrons to form a doping transition state between the conduction band (CB) and valence band (VB), which can restrict the recombination rate of electrons and holes effectively and lead to an outstanding enhancement of photooxidation performance. Furthermore, abundant highly reactive hydroxyl radicals (.OH) and superoxide radicals (.O2−), which are efficient intermediates with vivid oxidation ability, can further enhance the photocatalytic activity of RE‐doped CeO2. A cost‐effective strategy for designing CeO2‐based semiconductor photocatalysts doped with multitudinous RE ions that have enhanced photooxidation performance is presented in this paper.

Electron-ion recombination rate coefficients of carbon-like Ar12+

Electron-ion recombination of carbon-like Ar12+ forming Ar11+ has been investigated for the first time by using the cooler storage ring CSRm at the Institute of Modern Physics in Lanzhou, China. The absolute recombination rate coefficients are derived from the measurement in the electron-ion collision energy range of 0–50 eV, covering dielectronic recombination (DR) resonances associated with 2s22p2 and 2s2p3 (Δn = 0) core excitations. Theoretical results are obtained by employing FAC code and compared with the experimental recombination spectrum. An overall agreement is found in resonance energy positions between merged-beam and calculated spectra. Temperature dependent rate coefficients are derived from the measured DR spectrum by convoluting it with a Maxwell–Boltzmann energy distribution and compared with the calculations from the literature. In the presented temperature range 103–107 K, the experimentally derived rate coefficients agree with the theoretical results of Gu (2003 Astrophys. J. 590 1131) within the experimental uncertainties. The calculation by Zatsarinny et al (2004 Astron. Astrophys. 417 1173) underestimates the rate coefficients in the temperature range 103–5 × 104 K. The combination of the experimental results and theoretical calculation provides a benckmark for Ar12+ recombination data used in astrophysical modeling.

A rational design of excellent light-absorbing dyes with different N-substituents at the phenothiazine for high efficiency solar cells.

Dye-sensitized solar cells (DSSCs) have attracted great interest due to their simple fabrication process and low cost. However, most organic dyes with D-π-A configuration usually exhibit narrow absorption band, leading to poor light harvesting ability and great loss on photon conversion efficiency. In this research, a series of excellent light-absorbing dyes (CC202-I - CC202-III) with different N-substituents at phenothiazine entities based on the champion dye CC202 were designed and investigated by density functional theory (DFT) and time-dependent DFT (TD- DFT). According to the analysis of absorption property, the results demonstrated that different N-substituents (12-crown-4-substituted phenyl, 4-hexoxyphenyl, and bare phenyl) at phenothiazine entities lead to stronger and broader absorption band as well as red-shifted spectra; moreover, larger electronic injection driving force (ΔGinject), regeneration driving force (ΔGreg), capability of light harvested (ηLHE(λstrong)/η-LHEλ) and maximal photon generated current (Jph) in CC202-I - CC202-III are observed compared to that of CC202, which further increase JSC. Additionally, a larger VOC can be obtained in CC202-I - CC202-III due to larger dipole moment (unormal) and slow electron recombination rate. Considering the all calculated characteristics related to JSC and VOC, dyes with 12-crown-4-substituted phenyl, 4-hexoxyphenyl, and bare phenyl substituent on phenothiazine can effectively enhance the photoelectric conversion efficiency of DSSCs.

Graphitic carbon nitride nanoplatelets incorporated titania based type-II heterostructure and its enhanced performance in photoelectrocatalytic water splitting

In this present work, the synthesis of g-C3N4/TiO2 nanocomposites with different wt.% g-C3N4 to form a type-II heterostructure and its potential application towards photoelectrocatalytic water splitting was discussed. The synthesized g-C3N4 nanoplatelets incorporated TiO2 nanocomposites were characterized by various analytical techniques such as UV–vis diffuse reflectance spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and high-resolution transmission electron microscopy (HRTEM). HRTEM confirms the formation of type-II heterostructure consists of g-C3N4 nanoplatelets incorporated titania in the nanocomposite. The photoelectrocatalytic activity of the TiO2, g-C3N4, and g-C3N4/TiO2 nanocomposite were investigated under AM 1.5G (100 mW cm−2) illumination in 1 M KOH. The g-C3N4/TiO2 (with 10 wt.% of g-C3N4) nanocomposite photoanode exhibits photocurrent density of 142.7 μA cm−2 (at 1.23 V vs. RHE) which is ~ 1.8-fold higher than bare TiO2 (80.5 μA cm−2 at 1.23 V vs. RHE). The enhancement in PEC activity explained by formation of type-II heterostructure between g-C3N4 and TiO2, which reduced the recombination rate of photo-generated electron–hole pairs and also extends the absorption of TiO2 to visible light range and boost up the interfacial charge transfer between electrode/electrolyte interface, which enhance the PEC activity of the g-C3N4/TiO2 nanocomposite towards water splitting.

Visible light photocatalytic activity enhancing of MTiO3 perovskites by M cation (M = Co, Cu, and Ni) substitution and Gadolinium doping

The photocatalytic activity of the undoped and Gadolinium-doped MTiO3 perovskites (M = Co, Cu, and Ni) was investigated via degradation of methylene blue as a model organic pollutant under Xenon lamp as a visible light source. For this object, undoped and Gd-doped MTiO3 (M = Ni and Cu) perovskites were synthesized through the facile Pechini method, and an ethylene glycol-mediated route was used for the synthesis of undoped and Gd-doped CoTiO3. Synthesized perovskites were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), N2 adsorption/desorption and photoluminescence (PL) analysis. The results indicated that the photocatalytic activity of the MTiO3 perovskites (M = Co, Cu, and Ni) was improved by introducing 2% of Gd3+ ions into crystallite lattice of perovskites. The observed improvement can be attributed to the size decrease of perovskites, specific surface area enhancement, and decrement in the recombination rate of photogenerated electrons and holes resulted from doping Gd ions. 2% Gd-doped NiTiO3 represented the best photocatalytic activity. Moreover, the results demonstrated that methylene blue molecules are mainly degraded by photogenerated holes and superoxide anion radicals.

Enhancing the photocatalytic performance of g-C<sub>3</sub>N<sub>4</sub> for the degradation of Rhodamine B by Bi<sub>2</sub>MoO<sub>6</sub> modification

In this paper, spherical morphology Bi2MoO6 was synthesized by hydrothermal method, and Bi2MoO6 and g-C3N4 were heat treated to prepare g-C3N4/Bi2MoO6 composite photocatalysts with different mass ratios. By means of X-ray diffraction, scanning electron microscope, ultraviolet-visible spectrophotometer and fluorescence spectrum, the microstructure, size and morphology and optical properties of the samples were analyzed. The ideal matching band structures between g-C3N4 and Bi2MoO6 promote the carrier transfer, thus reducing the recombination rate of photo-generated electrons and holes, and improving the separation rate of photo-generated electrons and holes, so as to improve photocatalytic activity. Under visible light, g-C3N4/Bi2MoO6 composites show high degradation activity of Rhodamine B, and the photocatalytic performance is significantly improved than that of pure g-C3N4 and Bi2MoO6. The sample of the g-C3N4/Bi2MoO6 with mass ratio of 10% shows the best photocatalytic degradation performance, which is 6.5 and 3.3 times of g-C3N4 and Bi2MoO6, respectively.

Recent developments on the photoanodes employed in dye-sensitized solar cell

The emergence of dye sensitized solar cell (DSSC) as an alternative device for silicon based solar cell has gained a lot of attention from researchers due to its cost-effective, easy fabrication and environmentally friendliness. Photoanodes are semiconductor and as one of the four components of DSSC plays a major role for dye loading and electron conduction. A good photo anode should provide an efficient surface area in dye loading, nanostructure for high light harvesting opportunity, fast electron transport ability and good band gap architecture. Several nanostructures materials have been studied and employed as photoanode in DSSC. They include TiO2, ZnO, Nb2O5, SnO2, among others. The problem associated with photoanodes used in fabricating DSSC is high recombination rate of electrons that emanate from the number of grains. The dispersed nature of progress reports on developments of photoanodes calls for summary. Hence this review gives a general summary of the progress made in various materials used as photoanode in DSSC and the methods adopted in synthesizing them. In this present review, our attention is not only on synthesis and characterization of the materials alone but also on the effect of different factors influencing photovoltaic characteristics of photoanode for DSSC application.

Enhanced Visible Light Photocatalytic Activity of N and Ag Doped and Co-Doped TiO2 Synthesized by Using an In-Situ Solvothermal Method for Gas Phase Ammonia Removal

Single doping and co-doping of N and Ag on TiO2 were successfully prepared by using an in-situ solvothermal method and their structural properties and chemical compositions were characterized. The results indicated that all photocatalysts displayed in TiO2 anatase crystal phase, and a small mesoporous structure was observed in the doped materials. The main roles of N and Ag on the property and photocatalytic activity of TiO2 were different. The N doping has significantly enhanced homogenous surface morphology and specific surface area of the photocatalyst. While Ag doping was narrowing the band gap energy, extending light absorption toward a visible region by surface plasmon resonance as well as delaying the recombination rate of electron and hole of TiO2. The existence of N in TiO2 lattice was observed in two structural linkages such as substitutional nitrogen (Ti-O-N) and interstitial nitrogen (O-Ti-N). Silver species could be in the form of Ag0 and Ag2O. The photocatalytic performance of the photocatalysts coated on stainless steel mesh was investigated by the degradation of aqueous MB and gas phase NH3 under visible LED light illumination for three recycling runs. The highest photocatalytic activity and recyclability were reached in 5% N/Ag-TiO2 showing the efficiency of 98.82% for methylene blue (MB) dye degradation and 37.5% for NH3 removal in 6 h, which was 2.7 and 4.3 times, respectively. This is greater than that of pure TiO2. This was due to the synergistic effect of N and Ag doping.

Inverted pyramid Er3+ and Yb3+ Co-doped TiO2 nanorod arrays based perovskite solar cell: Infrared response and improved current density

In this study, a Yb3+, Er3+ co-doped TiO2 inverted pyramid nanorod (NR) array and a compact TiO2 film are simultaneously fabricated as the mesoporous support layer and electron-blocking layer, respectively, by a one-pot hydrothermal method. The scanning electron microscopy results show that the incorporation of Er3+ and Yb3+ causes changes not only in the growth rate of the NRs, but also in the TiO2 NR morphology. The Er3+, Yb3+ co-doped TiO2 NRs exhibit an inverted pyramidal morphology, which is beneficial for perovskite permeation and light utilization. Notably, the Er3+, Yb3+ co-doping causes changes in the band gap of TiO2 and leads to 25% increase in the current density. The electrochemical impedance spectroscopy results show that the device based on the doped TiO2 NRs has a higher recombination resistance and a lower transfer resistance than those of the undoped device, and thereby, the doped device exhibits a lower electron recombination rate. In addition, the upconversion Er and Yb co-doped device exhibits 25% higher current density and 17% higher photon-to-electron conversion efficiency, as revealed by the J-V test results. Moreover, the optimized efficiency of the TiO2 NR array-based perovskite solar cell is determined to be 10.02%. Furthermore, the Er and Yb co-doped device exhibits a near-infrared response, an efficiency of 0.1% is achieved under infrared light (800–1100 nm) irradiation. This upconversion material can widen the photovoltaic responses of solar cells into the near-infrared region and improve the utilization of sunlight.

Oligomeric Ruthenium Polypyridyl Dye for Improved Stability of Aqueous Photoelectrochemical Cells

Water-splitting dye-sensitized photoelectrochemical cells rely on molecular sensitizers to harvest light energy and drive the catalytic reactions necessary to generate hydrogen and oxygen from water. The desorption of sensitizer molecules from the semiconductor–aqueous electrolyte interface is a significant barrier to the practical implementation of these cells. To address this problem, we synthesized an oligomeric ruthenium dye ([RuP]n) that has dramatically improved stability as a photosensitizer for TiO2 electrodes over the pH range of interest (4–7.8) for DSPECs. Additionally, the efficiency of photoelectrochemical charge separation is known to depend on the rate of cross-surface hole diffusion between dye molecules. The oligomeric dye ([RuP]n) shows an order of magnitude faster cross-surface hole diffusion than the commonly used monomeric [Ru(bpy)2(4,4-PO3H2)2bpy]2+ (RuP) sensitizer. The enhanced stability of the polymeric dye also enables the use of intensity-modulated photovoltage spectroscopy to measure the recombination rate of photogenerated electrons and holes as a function of electrolyte pH.

Facile preparation of new nanohybrids for enhancing photocatalytic activity toward removal of organic dyes under visible light irradiation

In the present investigation, we have designed highly active titanium dioxide nanohybrids modified by various additives such as niobium oxide (Nb2O5), tin (IV) oxide (SnO2), reduced graphene oxide (RGO) and ceramic (SiO2/Fe3O4/ZrO2) by combining the hydrothermal and sol-gel methods. The prepared samples i.e. TiO2/Nb2O5/SnO2/RGO, TiO2/Ceramic/SnO2/RGO, TiO2/Nb2O5/SnO2 and TiO2/Ceramic/SnO2 were identified by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (including high-resolution imaging-HRTEM), Brunauer–Emmett–Teller (BET), ultraviolet–visible spectroscopy (UV–Vis), Diffuse reflectance spectroscopy (DRS) and fourier-transform infrared spectroscopy (FT-IR). Moreover, the photocatalytic performances of the newly designed nanohybrids were studied toward the photodegradation of crystal violet (CV) and methyl orange (MO) dyes under visible light illumination and the results were compared with those of previously reported TiO2/Nb2O5, TiO2/Ceramic and TiO2 nanoparticles. In this regard, the removal of chemical oxygen demand (COD) obeys the photodegradation. The TiO2/Nb2O5/SnO2/RGO sample displays a photocatalytic performance significantly larger than those of the other samples and also effectively decreases the recombination rate of electrons and holes.

Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm**Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0402300) and the National Natural Science Foundation of China (Grant Nos. U1932207, 11904371, and U1732133).

Recombination of Ar14+, Ar15+, Ca16+, and Ni19+ ions with electrons has been investigated at low energy range based on the merged-beam method at the main cooler storage ring CSRm in the Institute of Modern Physics, Lanzhou, China. For each ion, the absolute recombination rate coefficients have been measured with electron–ion collision energies from 0 meV to 1000 meV which include the radiative recombination (RR) and also dielectronic recombination (DR) processes. In order to interpret the measured results, RR cross sections were obtained from a modified version of the semi-classical Bethe and Salpeter formula for hydrogenic ions. DR cross sections were calculated by a relativistic configuration interaction method using the flexible atomic code (FAC) and AUTOSTRUCTURE code in this energy range. The calculated RR + DR rate coefficients show a good agreement with the measured value at the collision energy above 100 meV. However, large discrepancies have been found at low energy range especially below 10 meV, and the experimental results show a strong enhancement relative to the theoretical RR rate coefficients. For the electron–ion collision energy below 1 meV, it was found that the experimentally observed recombination rates are higher than the theoretically predicted and fitted rates by a factor of 1.5 to 3.9. The strong dependence of RR rate coefficient enhancement on the charge state of the ions has been found with the scaling rule of q3.0, reproducing the low-energy recombination enhancement effects found in other previous experiments.

Nitrogen deficient carbon nitride for efficient visible light driven tetracycline degradation: a combination of experimental and DFT studies

The narrow visible-light absorption range and a high recombination rate of photo-excited electrons and holes are the main reasons for the confined photocatalytic performance of graphitic carbon nitride (g-C3N4).

Investigation of the mechanism of overall water splitting in UV-visible and infrared regions with SnC/arsenene vdW heterostructures in different configurations.

Monolayer arsenene presents good stability and high photogenic carrier mobility. However, a high photogenic electron and hole pair recombination rate seriously reduces its photocatalytic activity. The photocatalytic activity can be effectively improved by building type II heterostructures. In this work, SnC/arsenene heterostructures in three configurations are studied using first-principles calculations. Their structure, stability, and electronic and photocatalytic properties are investigated. It is found that all SnC/arsenene heterostructures are stable, and form type-II band edges, which effectively promote the transfer of photogenerated electrons from the SnC monolayer to the arsenene sheet. The charge transfer between SnC and arsenene leads to a built-in electric field in the interface region, which is favorable for inhibiting photogenic electron and hole pair recombination. Compared with the monolayer arsenene, the photocatalytic activity is greatly improved and the absorption spectrum of SnC/arsenene heterostructures is expanded. Attractively, these three heterostructures present two different photocatalytic mechanisms. H1 and H3 configurations were taken as examples to study their photocatalytic properties for overall water splitting at varying pH values and external strains. We found that alkaline conditions were more favorable for photocatalysis of SnC/arsenene heterostructures. In particular, H3 can still achieve full photocatalytic water decomposition in the near infrared region. These results show that the SnC/arsenene heterostructures are a prospective material for photocatalysis application.

Complex scaling in relativistic calculations of cross sections for electron-ion recombination processes

SynopsisWe present an approach to calculate cross sections for electron-ion recombination processes. It is based on the combination of relativistic many-body perturbation theory and complex scaling method. A preliminary comparison between measured and calculated spectra for the electron-ion recombination rate coefficients for Be-like Ca will be given.

A study of velocity, temperature, and density in the plasma generated by laser-induced breakdowns

The paper presents velocity measurements of shock-induced flow field, leading to vortex generation and plasma deformation in air. Femtosecond-laser electronic excitation tagging (FLEET) velocimetry was performed at the times Δt = 3, 20, 50, and 100 µs post laser-induced breakdown. Emissions over Δt = 3–10 µs showed the propagations of the initially elliptic shock, transitioning into a spherical front. The shock emanated along the laser axis causes the flow outward, and then the pressure gradient generated by the rarefaction wave drives the inward flow at later moments, with the velocity magnitude approaching a steady-state value of 40 m s−1. Temporal velocity evolution was compared with non-self-similar solutions behind the propagating shock, which are sensitive to the size of the energy deposition, and the use of the measured initial plasma diameter reproduced the experiment. There establishes a region of uniform velocity around 35 m s−1 in the air-flow running through the plasma, which triggers the roll-up of the plasma surface by a large-scale vortex, providing the detail of flow field evolution from the shock propagation to the plasma deformation. A collective Thomson scattering and hybrid fs/ps pure rotational coherent anti-Stokes Raman scattering (CARS) were also performed to gain insight into the high-temperature plasma. An effective electron–ion recombination rate of 2 10−12 cm3 s−1 was measured at Δt = 0.5–10 µs, during a dynamic plasma expansion and compression. When the shock resides close to the plasma at Δt = 0.5–1 µs, the temperature distributions were found to follow the similarity law.

One step preparation of CN-WS2 nanocomposite with enhanced photoactivity and its application for photoelectrochemical detection of 5-formylcytosine in the genomic DNA of maize seedling

Carbon nitride and WS2 nanocomposite (CN-WS2) with excellent photoelectric activity was prepared by one-step thermal polymerization. By the new strategy of simultaneously loading C and N elements on pure WS2, the formation of CN-WS2 brings high mobility, ultra-fast charge carrier separation and transport, and slows down the recombination rate of electrons and holes. Then, a novel photoelectrochemical biosensor was constructed for 5-formylcytosine detection based on CN-WS2 composite, aldehyde reaction probe (ARP) and ZnFe2O4, where CN-WS2 composite was employed as photoactive material, ARP was used as 5-formylcytosine capture reagent, and ZnFe2O4 was adopted as artificial mimic enzyme. Under the catalysis effect of ZnFe2O4, 4-chloro-1-naphthol was quickly oxidized by H2O2 to produce the insoluble substance of benzo-4-chlorohexadienone, which would be deposited on the electrode surface and caused a decreased PEC response. Under optimal experimental conditions, the biosensor showed low detection limit of 3 pM. This method can also discriminate 5-formylcytosine with other cytosine derivatives. More importantly, the applicability of this method was demonstrated by assessing the effect of antibiotics on the content of 5-formylcytosine in the root, stem and leave of maize seedlings.

Photocatalytic reduction of CO2 over Sm-doped TiO2 nanoparticles

Highly efficient photocatalytic reduction of CO2 is essential for solving the greenhouse effect and energy crisis. In this paper, the Sm-TiO2 nanocomposites were successfully prepared via sol-gel method. The CO2 photoreduction activities of synthesized samples were tested under irradiation for 6 h and the results indicate that the 0.5% Sm-TiO2 catalyst has superior performance and stability. The CO and CH4 yields of 0.5% Sm-TiO2 catalyst are 55.47 and 3.82 μmol/g·cat respectively, which are 5.02 and 2.67 times the yield of TiO2. The possible mechanism of Sm doped TiO2 was investigated through comprehensive characterization and photoelectrochemical analysis. After the Sm doping, the photo-generated electrons in TiO2 could migrate to Sm 4f, and some of them can be captured by reducing Sm3+ to Sm2+, which can lower the recombination rate of electron and hole pairs. Therefore, the enhanced photocatalytic performance could be ascribed to large specific surface area, fast separation rate of electron–hole pairs and high visible light response. This report provides some meaningful attempts in researching the CO2 photocatalytic reduction.

Theoretical screening of high-efficiency sensitizers with D-π-A framework for DSSCs by altering promising donor group

Various types of organic dyes were synthesized to enhance efficiency over past years. Understanding structure-property relationships is a significant issue to develop novel dye for high efficiency dye-sensitized solar cells (DSSCs). In this work, three novel dyes (JY40-1–JY42-1) with ullazine as donor were designed based on the dye sensitizers JY40, JY41 and JY42, and their geometrical structures, absorption spectra as well as optical properties were theoretically investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT). Compared with original dyes, JY40-1–JY42-1 will exhibit better JSC due to higher light harvesting efficiency (LHE), regeneration driving force (ΔGinject), stronger and broader absorption spectra, superior ICT properties, and lower the driving force of regeneration (ΔGreg) as well as reorganization energy (λtotal). According to the analysis of interfacial interaction between the dye and electrolyte, JY40-1–JY42-1 have lower electron recombination rate, which further increase VOC. Hence, ullazine group as electron donor can effectively enhance efficiency of DSSCs according to the above analysis. In addition, JY42 exhibits a better balance in various important properties among three original dyes, which is in good agreement with the experimental results. This work provide a guidance for molecular engineering and screen high-efficiency sensitizers for DSSCs.

Nanocages of Polymeric Carbon Nitride from Low‐Temperature Supramolecular Preorganization for Photocatalytic CO2 Reduction

Polymeric carbon nitride (CN) is considered as one of the most promising photocatalysts to solve energy and environmental crises by solar‐to‐fuel conversion. However, the traditional thermal condensation of monomers usually leads to the disorganized agglomerate structure with a high recombination rate of electron–hole pairs. Herein, the effective synthesis of CN using supramolecular complexes of melamine and cyanuric acid with strengthened hydrogen bonding is presented, which are treated under freeze‐drying conditions as precursors. The as‐prepared CN exhibits a unique nanocage structure, which facilitates the scattering and reflection of incident light and improves the light‐harvesting efficiency. The charge transfer and CO2 adsorption of CNs is improved because of the extended π‐delocalization, conjugated aromatic system with more exposed lone‐pair electrons and a relatively enlarged specific surface area, caused by the more stretchable and distorted structure of CNs. Consequently, the nanocage‐like CN shows improved performance for photocatalytic CO2 reduction. This work provides a protocol for tailoring the microstructure of CNs via tuning the weak intermolecular interaction, with the aim of designing high‐performance CN‐based photocatalysts.