Cross-waveband optical computing imaging.

A novel, to the best of our knowledge, cross-spectral optical computing imaging experiment has been achieved through a single exposure of a charge-coupled device. The experimental setup integrates single-pixel imaging (SPI) with ghost imaging (GI) through a photoelectric conversion circuit and a synchronous modulation system. The experimental process involves modulation in one wavelength band (in SPI) and demodulation using the GI algorithm in another. Significantly, our approach utilizes optical computing demodulation, a departure from the conventional electronic demodulation in GI (SPI), which involves the convolution between the bucket optical signals and the modulated patterns on the digital micromirror device. A proof-of-concept cross-band imaging experiment from near-infrared to visible light has been carried out. The results highlight the system's ability to capture images at up to 20 frames per second using near-infrared illumination, which are then reconstructed in the visible light spectrum. This success not only validates the feasibility of our approach but also expands the potential applications in the SPI or GI fields, particularly in scenarios where two-dimensional detector arrays are either unavailable or prohibitively expensive in certain electromagnetic spectra such as x-ray and terahertz.

Thermal Transport in Pentagonal CX2 (X = N, P, As, and Sb).

Two-dimensional (2D) materials with a pentagonal structure have many unique physical properties and great potential for applications in electrical, thermal, and optical fields. In this paper, the intrinsic thermal transport properties of 2D pentagonal CX2 (X = N, P, As, and Sb) are comparatively investigated. The results show that penta-CN2 has a high thermal conductivity (302.7 W/mK), while penta-CP2, penta-CAs2, and penta-CSb2 have relatively low thermal conductivities of 60.0, 36.9, and 11.8 W/mK, respectively. The main reason for the high thermal conductivity of penta-CN2 is that the small atomic mass of the N atom is comparable to that of the C atom, resulting in a preferable pentagonal structure with stronger bonds and thus a higher phonon group velocity. The reduction in the thermal conductivity of the other three materials is mainly due to the gradually increased atomic mass from P to Sb, which reduces the phonon group velocity. In addition, the large atomic mass difference does not result in a huge enhancement of the anharmonicity or weakening of the phonon relaxation time. The present work is expected to deepen the understanding of the thermal transport of main group V 2D pentagonal carbons and pave the way for their future applications, also, providing ideas for finding potential thermal management materials.

Platelet-lymphocyte ratio as a predictor of lymph node metastasis in small bowel cancer.

The purpose of this research was to investigate the potential predictive value of preoperative systemic inflammatory indexes in identifying lymph node metastasis among patients diagnosed with small bowel cancer. A retrospective analysis of clinical data was conducted on small bowel cancer patients who underwent surgical treatment at the gastrointestinal surgery department of our hospital between January 2010 and June 2021. Patients were divided into groups based on the presence or absence of lymph node metastasis as confirmed by postoperative pathological results. The study compared the differences in preoperative inflammatory indexes and clinical data between the two groups using single factor analysis and multifactorial Logistic regression analysis. Furthermore, a nomogram model for predicting lymph node metastasis in colorectal cancer was constructed using R software and internally validated. The study sample consisted of 140 small bowel cancer patients,postoperative pathology confirmed lymph node metastasis in 72 cases. Univariate analysis results indicated associations between preoperative inflammatory indexes and clinical data with lymph node metastasis in small bowel cancer. Multifactorial logistic regression analysis revealed that gender, PLR, number of lymph node dissection, and lymphovascular invasion independently influenced lymph node metastasis in small bowel cancer patients. The developed nomogram model demonstrated a C-index of 0.855 (95% CI 0.792-0.917), with a calibrated prediction curve closely resembling the ideal curve. An elevated PLR is an independent risk factor for LNM in patients with small bowel cancer.

Monolayer 1T-Ag6S2 with Excellent Thermoelectric Properties.

We obtained a new material called monolayer 1T-Ag6S2 by replacing metal atoms in 1T phase transition-metal dichalcogenide sulfides (TMDs) with octahedral Ag6 clusters. Subsequently, the thermoelectric transport properties of monolayer 1T-Ag6S2 were systematically investigated using first-principles calculations and the generalized gradient approximation (GGA-PBE) exchange correlation functional. The findings demonstrate that monolayer 1T-Ag6S2 displays characteristics of a wide-bandgap semiconductor, with a bandgap of 2.48 eV. Notably, the incorporation of Ag6 clusters disrupts the structural symmetry, effectively enhancing the electronic structure and phonon properties of the material. Due to the flat valence band near the Fermi level, the extended relaxation time of the hole results in a greater effective mass compared to the electron, leading to a significant increase in the Seebeck coefficient. Under optimal doping conditions, the power factor of monolayer 1T-Ag6S2 can achieve 14.9 mW/mK2 at 500 K. The intricate crystal structure induces phonon path bending, reduces the overall frequency of phonon vibrations (<10 THz), and causes hybridization of low-frequency optical and acoustic branches, resulting in remarkably low lattice thermal conductivity (0.20 and 0.17 W/mK along the x and y axes at 500 K, respectively). The monolayer 1T-Ag6S2 demonstrates a remarkably high figure of merit ZT of 3.14 (3.15) on the x (y) axis at 500 K, significantly higher than those of conventional TMD materials. Such excellent thermoelectric properties suggest that monolayer 1T-Ag6S2 is a promising thermoelectric (TE) material. Our work reveals the deep mechanism of cluster substitution to optimize the thermoelectric properties of materials and provides a useful reference for subsequent research.

The inflammation score predicts the prognosis of gastric cancer patients undergoing Da Vinci robot surgery.

Neutrophil-to-lymphocyte ratio (NLR), calculated from peripheral blood immune-inflammatory cell counts, is considered a predictor of survival in various cancers. Nevertheless, there is a lack of research into the predictive value of NLR specifically in gastric cancer patients following surgery using the Da Vinci robot. Investigate the objectives of this research, confirm the positive predictive value of NLR in the prognosis of gastric cancer patients undergoing Da Vinci robotic-assisted surgery by comparing its prognostic ability with other inflammation markers and tumor biomarkers. In this retrospective analysis, information from 128 individuals diagnosed with gastric cancer and treated with da Vinci robot-assisted surgery was examined. The study examined various markers in the peripheral blood, including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), systemic immune-inflammatory index (SII) prognostic nutrition index (PNI), cancer antigen 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 72-4 (CA72-4), carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP).To ascertain the prognostic ability and optimal cutoff values of each parameter, operating characteristic curves and the area under the curve were utilized in the analysis. For evaluation of independent prognostic factors, we utilized Kaplan-Meier curves and multifactorial Cox analysis. The variables from the multifactorial Cox analysis were used to construct a nomogram. NLR, LMR, CEA, AFP, primary location, largest tumor size and TNM stage were all found to be significant predictive elements for overall survival (OS). Multivariate Cox identified NLR (P = 0.005), LMR (P = 0.03) and AFP (P = 0.007) as the only separate predictive variables among hematological indicators. The nomogram built using NLR demonstrates excellent predictive performance at 1 year (AUC = 0.778), 3 years (AUC = 0.773), and 5 years (AUC = 0.781). Cross-validation demonstrates that this model has favorable predictive performance and discriminative ability. NLR is an uncomplicated yet potent marker for forecasting the survival result of individuals with gastric cancer following da Vinci robotic surgery, and it possesses considerable predictive significance. The nomogram based on NLR provides patients with a visual and accurate prognosis prediction.

Investigation of the lattice thermal transport properties of Janus XClO (X = Cr, Ir) monolayers by first-principles calculations.

In the context of the global energy crisis, the development of high-performance heat transport devices within nano scales has become increasingly important. Theoretical discovery and evaluation of novel structures with high performance in thermal conductivity by affordable calculations could provide significant instructions for experimental studies focusing on thermoelectric device development. For 2-dimensional (2D) functional materials, their heat transport efficiency is correlated with their electronic properties and structural features. In this study, we computationally investigated the heat transport within Janus XClO (X = Cr, Ir); its structural and electronic properties were well solved by first-principles calculations. Furthermore, to evaluate thermodynamics stability and applicability, ab initio molecular dynamics (AIMD) simulations are conducted. Through a benchmarking study upon these XClO monolayers with different compositions, we noticed that their heat transport efficiency is associated with the percentage of doped magnetic atoms. The theoretical insights provided by this study are highly instructive for future experimental studies focusing on thermal device development.

Li Decorated Penta-BCN as a Competitive Reversible Hydrogen Storage Media: A First-Principles Study.

Efficient storage media are crucial for practical applications of hydrogen, which is the most promising clean energy resource. In addition to possessing a highly reversible gravimetric capacity, the stability and superlight mass of potential storage media should not be underestimated. In this study, we exploit the light mass and unique puckered structure of penta-BCNs to design Li-decorated penta-BCNs for hydrogen storage via a series of first-principles calculations. Our results reveal that Li atoms can form stable chemical complexes with the surface of penta-BCNs with an average binding energy of -2.21 eV without causing deformation. Each Li@penta-BCN unit can physically adsorb up to 27H2 molecules, and the highest hydrogen storage capacity can reach 7.44 wt %, with an average adsorption energy of -0.16 eV/H2, surpassing the target value of 5.5 wt % set by the U.S. Department of Energy. Further elaborate analysis of the electronic structure shows the polarization enhancement mechanism, which is caused by charge transfer from Li atoms to the penta-BCN surface. Our results indicate that Li-decorated penta-BCN could be a promising hydrogen storage material for further application and inspire the theoretical or experimental design of novel materials for clean energy.

Strain-Driven High Thermal Conductivity in Hexagonal Boron Phosphide Monolayer.

Two-dimensional graphenelike material, hexagonal boron phosphide (h-BP), is a promising candidate for electronic and optoelectronic devices because of its suitable band gap and high carrier mobility. Especially from the ultrahigh lattice thermal conductivity (κl), it exhibits great potential to solve the challenges of future thermal management applications. Here, the excellent lattice thermal transport properties of the h-BP monolayer are systematically analyzed at the atomic level based on the first-principles method. The results show that the ultrahigh κl value of the h-BP monolayer is attributed to its high phonon group velocity and long phonon lifetime and the strong phonon hydrodynamic effect. We further explore the influence of the tensile strain on the thermal transport properties of the h-BP monolayer. As the strain increases from 0 to 8%, the κl value shows a trend of first increasing and then decreasing due to the coeffect of strain-driven changes for phonon harmonicity and anharmonicity. Under a strain of 6%, the κl value of the h-BP monolayer is as high as 795 W/mK at 300 K, which is about 2.22 times larger than that of 357 W/mK without strain. Such a significant increase in the κl value is mainly due to the increased phonon group velocity and decreased Grüneisen parameter caused by strain. This work is helpful to understand the critical role of tensile strain in lattice thermal transport of two-dimensional graphenelike materials. It is conducive to promoting the thermal management application of the h-BP monolayer.

Effect of atomic substitution and structure on thermal conductivity in monolayers H-MN and T-MN (M = B, Al, Ga).

Finding materials with suitable thermal conductivity (κ) is crucial for improving energy efficiency, reducing carbon emissions, and achieving sustainability. Atomic substitution and structural adjustments are commonly used methods. By comparing the κ of two different structures of two-dimensional (2D) IIIA-nitrides and their corresponding carbides, we explored whether atomic substitution has the same impact on κ in different structures. All eight materials exhibit normal temperature dependence, with κ decreasing as the temperature rises. Both structures are single atomic layers of 2D materials, forming M-N bonds, with the difference being that H-MN consists of hexagonal rings, while T-MN consists of tetragonal and octagonal rings. 2D IIIA-nitrides provide a good illustration of the impact of atomic substitution and structure on κ. On a logarithmic scale of κ, it approximates two parallel lines, indicating that different structures exhibit similar trends of κ reduction under the same conditions of atomic substitution. We analyzed the mechanisms behind the decreasing trend in κ from a phonon mode perspective. The main reason for the decrease in κ is that heavier atoms lower lattice vibrations, reducing phonon frequencies. Electronegativity increases, altering bonding characteristics and increasing anharmonicity. Reduced symmetry in complex structures decreases phonon group velocities and enhances phonon anharmonicity, leading to decreased phonon lifetimes. It's noteworthy that we found that atomic substitution and structure significantly affect hydrodynamic phonon transport as well. Both complex structures and atomic substitution simultaneously reduce the effects of hydrodynamic phonon transport. By comparing the impact of κ on two different structures of 2D IIIA-nitrides and their corresponding carbides, we have deepened our understanding of phonon transport in 2D materials. Heavier atomic substitution and more complex structures result in reduced κ and decreased hydrodynamic phonon transport effects. This research is likely to have a significant impact on the study of micro- and nanoscale heat transfer, including the design of materials with specific heat transfer properties for future applications.

Skin-Inspired, Highly Sensitive, Broad-Range-Response and Ultra-Strong Gradient Ionogels Prepared by Electron Beam Irradiation.

Skin, characterized by its distinctive gradient structure and interwoven fibers, possesses remarkable mechanical properties and highly sensitive attributes, enabling it to detect an extensive range of stimuli. Inspired by these inherent qualities, a pioneering approach involving the crosslinking of macromolecules through in situ electron beam irradiation (EBI) is proposed to fabricate gradient ionogels. Such a design offers remarkable mechanical properties, including excellent tensile properties (>1000%), exceptional toughness (100 MJ m-3 ), fatigue resistance, a broad temperature range (-65-200°C), and a distinctive gradient modulus change. Moreover, the ionogel sensor exhibits an ultra-fast response time (60 ms) comparable to skin, an incredibly low detection limit (1 kPa), and an exceptionally wide detection range (1 kPa-1 MPa). The exceptional gradient ionogel material holds tremendous promise for applications in the field of smart sensors, presenting a distinct strategy for fabricating flexible gradient materials.

First-principles study of Li-doped planar g-C3N5 as reversible H2 storage material.

Under the background of energy crisis, hydrogen owns the advantage of high combustion and shows considerable environment friendliness; however, to fully utilize this novel resource, the major hurdle lies in its delivery and storage. The development of the in-depth yet systematical methodology for two-dimensional (2D) storage media evaluation still remains to be challenging for computational scientists. In this study, we tried our proposed evaluation protocol on a 2D material, g-C3N5, and its hydrogen storage performance was characterized; and with addition of Li atoms, the changes of its electronical and structural properties were detected. First-principles simulations were conducted to verify its thermodynamics stability; and, its hydrogen adsorption capacity was investigated qualitatively. We found that the charges of the added Li atoms were transferred to the adjacent nitrogen atoms from g-C3N5, with the formation of chemical interactions. Thus, the isolated metallic sites tend to show considerable electropositivity, and can easily polarize the adsorbed hydrogen molecules, and the electrostatic interactions can be enhanced correspondingly. The maximum storage capacity of each primitive cell can be as high as 20 hydrogen molecules with a gravimetric capacity of 8.65 wt%, which surpasses the 5.5 wt% target set by the U.S. Department of Energy. The average adsorption energy is ranged from -0.22 to -0.13 eV. We conclude that the complex 2D material, Li-decorated g-C3N5 (Li@C3N5), can serve as a promising media for hydrogen storage. This methodology provided in this study is fundamental yet instructive for future 2D hydrogen storage materials development.

The intrinsically low lattice thermal conductivity of monolayer T-Au6X2 (X = S, Se and Te).

Thermal conductivity (κ, which consists of electronic thermal conductivity κe and lattice thermal conductivity κl), as an essential parameter in thermal management applications, is a critical physical quantity to measure the heat transfer performance of materials. To seek low-κ materials for heat-related applications, such as thermoelectric materials and thermal barrier coatings. In this study, based on a complex cluster design, we report a new class of two-dimensional (2D) transition metal dichalcogenides (TMDs): T-Au6X2 (X = S, Se, and Te) with record ultralow κl values. At room temperature, the κl values of T-Au6S2, T-Au6Se2, and T-Au6Te2 are 0.25 (0.23), 0.30 (0.21), and 0.12 (0.10) W m-1 K-1 along the x-axis (y-axis) direction, respectively, exhibiting good thermal insulation. The ultralow κl originates from strong phonon softening and suppression, especially for the phonon with frequency 0-1 THz. In addition, T-Au6Te2 holds the lowest group velocity and phonon relaxation time among the three T-Au6X2 monolayers. Our study provides an alternative approach for achieving ultralow κl through complex cluster replacement. Meanwhile, this new class of TMDs is expected to shine in thermal insulation and thermoelectricity due to their ultralow κl values.

Layer-dependent excellent thermoelectric materials: from monolayer to trilayer tellurium based on DFT calculation.

Monoelemental two-dimensional (2D) materials, which are superior to binary and ternary 2D materials, currently attract remarkable interest due to their fascinating properties. Though the thermal and thermoelectric (TE) transport properties of tellurium have been studied in recent years, there is little research about the thermal and TE properties of multilayer tellurium with interlayer interaction force. Herein, the layer modulation of the phonon transport and TE performance of monolayer, bilayer, and trilayer tellurium is investigated by first-principles calcuations. First, it was found that thermal conductivity as a function of layer numbers possesses a robust, unusually non-monotonic behavior. Moreover, the anisotropy of the thermal transport properties of tellurium is weakened with the increase in the number of layers. By phonon-level systematic analysis, we found that the variation of phonon transport under the layer of increment was determined by increasing the phonon velocity in specific phonon modes. Then, the TE transport properties showed that the maximum figure of merit (ZT) reaches 6.3 (p-type) along the armchair direction at 700 K for the monolayer and 6.6 (p-type) along the zigzag direction at 700 K for the bilayer, suggesting that the TE properties of the monolayer are highly anisotropic. This study reveals that monolayer and bilayer tellurium have tremendous opportunities as candidates in TE applications. Moreover, further increasing the layer number to 3 hinders the improvement of TE performance for 2D tellurium.

Construction of highly active FeN4@Fex(OH)y cluster composite sites for the oxygen reduction reaction and the oxygen evolution reaction.

Seeking cost-effective and earth-abundant electrocatalysts with excellent activity for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in zinc-air batteries (ZABs) is critically important. In this work, the ORR and OER performance of the Fex cluster supported on FeN4 composite sites (FeN4@Fex) is investigated based on density functional theory. Based on the charge density difference between the Fex cluster and the FeN4 substrate, the conclusion that the decreased charge density of the chemical bond between the metal and the adsorbate can weaken the adsorption of the adsorbate can be drawn. The results of the d-band center also confirm this. Furthermore, the ORR and OER free energy change profiles show that FeN4@Fe8 exhibits the best ORR and OER activity. This is because the electronic environment regulated by the Fex cluster can improve the adsorption of intermediates, which is conducive to enhancing catalytic activity. Further considering the solution environment, the activity of FeN4@Fex with preadsorbed OH (FeN4@Fex(OH)y) was studied. It is found that FeN4@Fe8(OH)6 is still the best catalyst. This work introduces new highly active composite sites for catalyzing the ORR in an acid medium.

Strong anisotropy of Sc2X2Se2 (X = Cl, Br, I) monolayers contributes to high thermoelectric performance.

As a novel type of anisotropic two-dimensional material, extensive attention has been paid to the thermoelectric (TE) properties of FeOCl-type monolayers, such as Al2X2Se2 (X = Cl, Br, I), Sc2I2S2, and Ir2Cl2O2. Recently, theoretical works based on first-principles calculations have been powerful driving forces in field of TE research. In this work, we perform an investigation into the TE properties of Sc2X2Se2 (X = Cl, Br, I) monolayers based on density functional theory (DFT). A study on the stability, including AIMD simulation and phonon calculation, shows the stable structure of Sc2Cl2Se2, Sc2Br2Se2, and Sc2I2Se2 monolayers. Additionally, the electronic and thermal transport properties of Sc2X2Se2 monolayers are anisotropic along the x and y directions. Moreover, the combination of excellent Seebeck coefficient and ultralow lattice thermal conductivity contributes to outstanding ZT values, and the ZT values follow the order: Sc2I2Se2 > Sc2Br2Se2 > Sc2Cl2Se2. At 300 K, we obtained maximum ZT of 0.34, 0.77, and 1.97 for Sc2Cl2Se2, Sc2Br2Se2, and Sc2I2Se2, respectively, by n-type doping in the x direction. These results demonstrate that monolayer Sc2X2Se2 (X = Cl, Br, I) materials are promising thermoelectric materials, Sc2I2Se2 has more desirable properties along the x direction, and n-type doping can significantly enhance the ZT values. Our work lays a foundation for exploring the TE transport properties of FeOCl-type monolayers.

Reversible Hydrogen Storage Media by g-CN Monolayer Decorated with NLi4: A First-Principles Study.

A two-dimensional graphene-like carbon nitride (g-CN) monolayer decorated with the superatomic cluster NLi4 was studied for reversible hydrogen storage by first-principles calculations. Molecular dynamics simulations show that the g-CN monolayer has good thermal stability at room temperature. The NLi4 is firmly anchored on the g-CN monolayer with a binding energy of -6.35 eV. Electronic charges are transferred from the Li atoms of NLi4 to the g-CN monolayer, mainly due to the hybridization of Li(2s), C(2p), and N(2p) orbitals. Consequently, a spatial local electrostatic field is formed around NLi4, leading to polarization of the adsorbed hydrogen molecules and further enhancing the electrostatic interactions between the Li atoms and hydrogen. Each NLi4 can adsorb nine hydrogen molecules with average adsorption energies between -0.152 eV/H2 and -0.237 eV/H2. This range is within the reversible hydrogen storage energy window. Moreover, the highest achieved gravimetric capacity is up to 9.2 wt%, which is superior to the 5.5 wt% target set by the U.S. Department of Energy. This study shows that g-CN monolayers decorated with NLi4 are a good candidate for reversible hydrogen storage.

Heat transport properties of novel carbon monolayer (net-Y): a comparative study with graphene.

With the rapid development of material preparation and quantum computation technologies, the discovery of superior electronic devices in the nanoscale has been widely facilitated. For materials for application in thermoelectric and thermal conductivity devices, their overall performance can be demonstrated by their inner heat transport efficiency. Thus, fundamental elucidation of the heat transport mechanism within low-dimensional materials with physical insight, is of great significance for novel electric device development. In addition, theoretical clarification can also help with the efficient control of the developed thermal devices, and furthermore, provide strategies to improve the efficiency of heat conversion. In this study, we focus on a novel carbon monolayer (net-Y) that is composed of sp2 hybridized C atoms, we systematically assess its practical applicability in electronic device design by conducting first-principles calculations. Furthermore, to obtain in-depth understanding of the factors that determine its heat transport efficiency, its mechanical and phonon spectrum related properties were also investigated. Through a comparative study with graphene, the heat transport mechanism of net-Y was successfully summarized; the methodology and theoretical findings presented in this study could provide an instructive reference for future experimental work.

Lower thermal conductivity of body centered cubic carbon (C14): a comparative study with diamond.

In recent years, the material preparation technology has ushered into a stage of rapid development, increasingly more carbon materials are found to display superior properties, making them suitable for designing nano-scale devices. Within the applications of electronic devices, a considerable amount of consumed energy has to be converted into heat; thus the efficiency of heat transport inside these devices can largely determine their overall performance. Decent elucidations of the heat transport mechanisms within low-dimensional materials will be helpful to achieve thermal management control of the related devices and furthermore, to improve their conversion efficiency. It is well understood that the heat transport within these kinds of materials is largely associated with their structural features. In this study, we focused on a novel material, body centered cubic carbon (C14), which is composed of sp3 hybridized carbon atoms. Such a novel material displays superior electronic properties; however, its thermal properties remain to be investigated. In order to systematically evaluate the practical applicability of this novel material, first-principles calculations were employed to systematically solve its structure; furthermore, its thermal conductivity, phonon dispersion spectrum, phonon properties, Grüneisen parameters, scattering phase space and mechanical properties were all described in detail. We found that C14 performs well in heat transport; and via systematical comparison with another allotrope, diamond, its transport mechanism was further summarized. We hope the physical insights provided by this study could serve as theoretical support for nano-scale device design.

Computational Evaluation of Al-Decorated g-CN Nanostructures as High-Performance Hydrogen-Storage Media.

Density functional theory (DFT) calculations were employed to solve the electronic structure of aluminum (Al)-doped g-CN and further to evaluate its performance in hydrogen storage. Within our configurations, each 2 × 2 supercell of this two-dimensional material can accommodate four Al atoms, and there exist chemical bonding and partial charge transfer between pyridinic nitrogen (N) and Al atoms. The doped Al atom loses electrons and tends to be electronically positive; moreover, a local electronic field can be formed around itself, inducing the adsorbed H2 molecules to be polarized. The polarized H2 molecules were found to be adsorbed by both the N and Al atoms, giving rise to the electrostatic attractions between the H2 molecules and the Al-doped g-CN surface. We found that each 2 × 2 supercell can adsorb at most, 24 H2 molecules, and the corresponding adsorption energies ranged from -0.11 to -0.31 eV. The highest hydrogen-storage capacity of the Al-doped g-CN can reach up to 6.15 wt%, surpassing the goal of 5.50 wt% proposed by the U.S. Department of Energy. Additionally, effective adsorption sites can be easily differentiated by the electronic potential distribution map of the optimized configurations. Such a composite material has been proven to possess a high potential for hydrogen storage, and we have good reasons to expect that in the future, more advanced materials can be developed based on this unit.