Combination Of Modes Research Articles

Properties of focused combined modes of terahertz laser

Physical features of spatial-energy characteristics of linearly polarized THz laser beams at sharp and moderate focusing in free space are analyzed both theoretically and experimentally. The Rayleigh–Sommerfeld vector theory is used to model propagation of laser beams excited by quasi-optical waveguide resonator modes in free space. Well-known methods of measuring spatial-energy characteristics of laser beams in the THz range are used in the experimental study. It is shown that the intensity of the total electric field of both combined TE0n + EH2n and EН–1n + EH3n modes (n = 1, 2, 3) in the focal region is defined by all three components and has a dip on the axis for both focusing types. The central maxima of the field of these modes become significantly shifted from the geometric foci of the lenses used as the order n of these modes increases. The EН–11 + EH31 mode has the smallest diameter (2.94λ) of the focal spot in the maximum intensity region at sharp focusing. The TE01 + EH21 mode has the smallest diameter (13.65λ) of the focal spot at moderate focusing.

Hierarchical Protofilament Intertwining Rules the Formation of Mixed-Curvature Amyloid Polymorphs.

Amyloid polymorphism is a hallmark of almost all amyloid species, yet the mechanisms underlying the formation of amyloid polymorphs and their complex architectures remain elusive. Commonly, two main mesoscopic topologies are found in amyloid polymorphs characterized by non-zero Gaussian and mean curvatures: twisted ribbons and helical fibrils, respectively. Here, a rich heterogeneity of configurations is demonstrated on insulin amyloid fibrils, where protofilament packing can occur, besides the common polymorphs, also in a combined mode forming mixed-curvature polymorphs. Through AFM statistical analysis, an extended array of heterogeneous architectures that are rationalized by mesoscopic theoretical arguments are identified. Notably, an unusual fibrillization pathway is also unraveled toward mixed-curvature polymorphs via the widespread recruitment and intertwining of protofilaments and protofibrils. The results present an original view of amyloid polymorphism and advance the fundamental understanding of the fibrillization mechanism from single protofilaments into mature amyloid fibrils.

Cooperative control of multiple magnetically controlled soft robots

Multiple magnetically controlled soft robots are more efficient in terms of task execution. However, how to realize such multiple robots moving along the respective different paths is still a challenge since they are in one driving magnetic field. In order to deal with this problem, this paper proposes a cooperative control method by fusing their parallel cooperative motion (multiple robots moving simultaneously) and their independent cooperative motion (single robot moving). Yet, there are two strong couplings in the fusion of such two cooperative motions, which makes the control more difficult. Thus, an enumeration-based decoupling algorithm is developed for the first combined mode coupling, and the speed of each robot is planned for the second motion speed coupling. Then, a neural network-based controller is developed to achieve the respective speed control simultaneously of multiple robots, and the deviation limiting controller is constructed to compensate the deviation angle. Finally, through the actual experiments, it is verified that the proposed method realizes effectively the motion of two robots along different paths and the mean absolute error of speed is about 0.1091 mm/s and 0.2118 mm/s, while the mean absolute error of tracking is about 0.3369 mm and 0.4454 mm, respectively.

Incorporating multi-source remote sensing in the detection of earthquake-damaged buildings based on logistic regression modelling

After an earthquake, efficiently and accurately acquiring information about damaged buildings can help reduce casualties. Earth observation data have been widely used to map affected areas after earthquakes. However, fine post-earthquake assessment results are needed to manage recovery and reconstruction and to estimate economic losses. In this paper, for quantification and precision purposes, a method of earthquake-induced building damage information extraction incorporating multi-source remote sensing data is proposed. The method consists of three steps： (1) Analysis of multisource features that describe texture, colour, and geometry, (2) rough set theory is carried out to further determine the feature parameters, (3) Logistic regression model (LRM) was built to describe the relationship between the occurrence and absence of destroyed buildings within an individual object. Old Beichuan County (centered at approximately 31.833︒N, 104.459° E), China, the area most devastated by the Wenchuan earthquake on May 12, 2008, is used to test the proposed hypothesis. Multi-source remote sensing imagery include optical data, synthetic aperture radar (SAR) data, and digital surface model (DSM) data generated by interpolating light detection and ranging (LiDAR) point cloud data. Through comparison with the ground survey, the experimental results show that the detection accuracy of the proposed method is 94.2 %; the area under the receiver operating characteristic (ROC) curve is 0.827. The efficiency of the proposed method is demonstrated using 6 modes of data combination acquired from the same area in old Beichuan County. The approach is one of the first attempts to extract damaged buildings through the fusion of three types of data with different features. The approach addresses multivariate regression methodologies and compares the potential of features for application in the damage detection field.

Analysis of bending and torsional modal of PMSM rotor systems for EV

Abstract The rotor system is crucial in the all-in-one integrated power system of EV, making the study of its dynamic mechanical performance at high speeds imperative. This paper focuses on analyzing the modal characteristics of EV rotor systems and the impact of individual components on bending and torsional vibrations. Using finite element analysis (FEA), a modal analysis of a 100 kW high-speed electric motor rotor is conducted, followed by experimental tests using an exciting method. Comparing simulation with experimental results reveals how end caps and bearings reduce the rotor’s bending natural frequency (BNF), while the core increases it. Additionally, the addition of rotor components leads to varied reductions in the rotor’s torsional natural frequency (TNF). Furthermore, the error between FEA and experimental values for combined rotor modes remains within 3.53%, affirming the accuracy and reliability of the analysis in predicting rotor modal characteristics.

An Optical Study on the Ignition and Flame Development Initiated by a Combination of Passive Pre-Chamber and Spark Ignition

ABSTRACT Pre-chamber jet ignition combined with spark ignition in main chamber has advantages in adjusting the combustion phase and improving the burning rate for spark ignition engines. In this study, optical experiments based on a constant volume combustion chamber and high-speed schlieren imaging were conducted to investigate the ignition and flame development under the combined ignition mode with a passive pre-chamber and spark plug using methane fuel. Two modes of flame development were observed with different ignition time interval of pre-chamber ignition and spark ignition (Δt ign). At relatively short Δt ign, the “jet-disturbed flame” mode occurs with a three-stage combustion process: laminar flame; flame acceleration by jet-flame interaction and re-ignition at the jet root; flame deceleration. The maximum global flame speed can be increased from 2 m/s to 9 m/s under λ = 1 and from 1 m/s to 5.5 m/s under λ = 1.3. The ignition delay is relatively short and the heat release shows a slow and multi-stage feature. Moreover, the ignition delay and combustion duration in main chamber are relatively not sensitive to the variation of nozzle diameter. As the spark ignition becomes later (longer Δt ign), the “spark-initiated turbulent flame” mode occurs. In this mode, a rapidly developing turbulent flame is initiated by the spark plug, with a global flame speed up to 16 ~ 18 m/s under λ = 1 and 6 ~ 11 m/s under λ = 1.3. Compared with pre-chamber ignition, a shorter combustion duration is obtained at certain Δt ign and misfire can be avoided because of the synergy of the combined ignition mode.

Cobalt-substituted porous calcium copper titanate electrodes for paracetamol degradation by an electro-oxidation/peroxymonosulfate system

Developing cobalt-substituted perovskite electroactive membranes with an efficient Co/Cu combination mode is an important environmental challenge for removing drugs via peroxymonosulfate (PMS) activation. In this work, cobalt (Co)-substituted calcium copper titanatewas synthesized with an easy ball milling process and used as an anode in electro-oxidation in the presence of PMS for paracetamol degradation. The Co-CCTO anode with a Co ratio of 0.5 showed the highest removal efficiency (100 % of 10 ppm paracetamol after 180 min) due to the increase of the active sites and the appearance of the Co2+/Co3+ cycle that accelerates the charge transfer with Co incorporation into the lattice. Scavenger experiments showed that sulfate radicals (SO4̇−), oxygen radicals (O2̇-), hydroxyl radicals (̇OH), and singlet oxygen (1O2) were generated in the electro-oxidation-PMS reaction system and that SO4̇−, 1O2, and O2̇- were the dominant active radicals. The toxicity tests with Vibrio fischeri confirmed paracetamol mineralization and decomposition and the elimination of harmful by-products. It is crucial to explore the substitution of CCTO with different metal dopants in order to optimize the membrane performance and overcome the limitations associated with cobalt substitution.

Experimental analysis of building envelope integrating phase change material and cool paint under a real environment in autumn

The application of phase change material (PCM) and cool paint (CP) to building envelope is one of the effective solutions to improve thermal comfort of passive buildings. Therefore, the thermal performance of buildings in Hefei, China in autumn is compared and analyzed by integrating PCM and CP into the building envelope. According to the comprehensive analysis of indoor thermal environment and the ability to maintain indoor thermal comfort, it is concluded that the combined application of PCM and CP is better than the application of PCM or CP alone. And the combination of PCM and CP laid on the south wall and roof respectively is the best. It is more suitable for commercial buildings, which can prolong indoor air temperature (Ti) in the thermal comfort zone for more than 10 h during the day. The combination of PCM and CP laid on the roof can prolong Ti in the thermal comfort zone for more than 8.05 h, which is more suitable for residential buildings. The purpose is to explore the best combination mode of residential and commercial buildings according to the characteristics of temperature change and building types (according to people's main use time) in the real environment.

JWST detections of amorphous and crystalline HDO ice toward massive protostars

Tracing the origin and evolution of interstellar water is key to understanding many of the physical and chemical processes involved in star and planet formation. Deuterium fractionation offers a window into the physicochemical history of water due to its sensitivity to local conditions. The aim of this work is to utilize the increased sensitivity and resolution of the James Webb Space Telescope (JWST) to quantify the HDO/H$_ $O ratio in ices toward young stellar objects (YSOs) and to determine if the HDO/H$_ $O ratios measured in the gas phase toward massive YSOs (MYSOs) are representative of the ratios in their ice envelopes. Two protostars observed in the Investigating Protostellar Accretion (IPA) program using JWST NIRSpec were analyzed: HOPS 370, an intermediate-mass YSO (IMYSO), and IRAS 20126+4104, a MYSO. The HDO ice toward these sources was quantified via its 4.1 mu m band. The contributions from the CH$_ $OH combination modes to the observed optical depth in this spectral region were constrained via the CH$_ $OH 3.53 mu m band to ensure that the integrated optical depth of the HDO feature was not overestimated. H$_ $O ice was quantified via its 3 mu m band. New laboratory IR spectra of ice mixtures containing HDO, H$_ $O, CH$_ $OH, and CO were collected to aid in the fitting and chemical interpretation of the observed spectra. HDO ice is detected above the 3sigma level in both sources. It requires a minimum of two components, one amorphous and one crystalline, to obtain satisfactory fits. The H$_ $O ice band at 3 mu m similarly requires both amorphous and crystalline components. The observed peak positions of the crystalline HDO component are consistent with those of annealed laboratory ices, which could be evidence of heating and subsequent recooling of the ice envelope (i.e., thermal cycling). The CH$_ $OH 3.53 mu m band is fit best with two cold components, one consisting of pure CH$_ $OH and the other of CH$_ $OH in an H$_ $O-rich mixture. From these fits, ice HDO/H$_ $O abundance ratios of 4.6pm 1.8times 10$^ $ and 2.6pm 1.2times 10$^ $ are obtained for HOPS 370 and IRAS 20126+4104, respectively. The simultaneous detections of both crystalline HDO and crystalline H$_ $O corroborate the assignment of the observed feature at 4.1 mu m to HDO ice. The ice HDO/H$_ $O ratios are similar to the highest reported gas HDO/H$_ $O ratios measured toward MYSOs and the hot inner regions of isolated low-mass protostars, suggesting that at least some of the gas HDO/H$_ $O ratios measured toward massive hot cores are representative of the HDO/H$_ $O ratios in ices. The need for an H$_ $O-rich CH$_ $OH component in the CH$_ $OH ice analysis supports recent experimental and observational results that indicate that some CH$_ $OH ice may form prior to the CO freeze-out stage in H$_ $O-rich ice layers.

Analysis of compression deformation of water-lubricated bearing material based on rigid and flexible substances coupled with microstructure

Water-lubricated bearings are pivotal components in ship propulsion shafting, The mechanical properties of composite materials serve as the foundation for water-lubricated bearing materials. In this paper, taking the 3D composite structure material of arthropod outer carapace as a biological model, a bionic design of a water-lubricated bearing composite material based on rigid and flexible substances coupled with microstructure is proposed, and its load-carrying properties are analyzed through simulation and experimentation. The research results showed that the rigid fiber helix angle of 30° would be better for enhancing mechanical performance. When the basic parameters of the RVE (representative volume elements) are determined, the arrangement of it will also affect the mechanical properties of the composite material to a certain extent, and from the test results, the three RVEs combination mode can obtain better bearing capacity.

Optimization of laser-induced graphene membrane for simultaneous photo- and electro-thermal membrane distillation

To optimize the Laser-Induced Graphene (LIG) Janus membrane, this study investigated the effects of membrane pore structure, polydimethylsiloxane (PDMS) coating sequence and addition of silver (Ag) nanoparticles on membrane distillation (MD) performance. This study aimed to enhance the photothermal characteristics of graphene while using the intrinsic electrical conductivity for simultaneous photo- and electrothermal MD. Operating at the same photo- and electro-thermal power input, the LIG Janus membrane made by treating the membrane face with smaller pores (i.e., shiny side) gave an improved flux performance of up to 53.6% and a decrease in specific energy of 35.4% compared to that by treating the membrane face with larger pores (i.e., dull side). The effect of the PDMS coating sequence also depended on the pore structure. For the face with smaller pore structures, coating PDMS before laser irradiation (PDMS-BLSS) gave a flux improvement of up to 24.5% and a decrease in specific energy of 19.7%, compared to coating PDMS after laser irradiation (PDMS-ALSS). As for the face with larger pore structures, coating PDMS before laser irradiation (PDMS-BLDS) resulted in a flux reduction of up to 20.8% and an increase in specific energy of 27.1%, compared to coating PDMS after irradiation (PDMS-ALDS). The LIG Janus membranes embedded with Ag nanoparticles led to improved photothermal heating properties, improving flux by 43.1–65.8% and decreasing specific energy by 15.2–30.5% while maintaining similar electrothermal heating properties. Carrying out simultaneous photo- and electro-thermal MD indicates that only the Ag-doped Janus LIG membrane gave a synergistic effect whereby the flux of the combined heating mode was higher than the summation of the fluxes obtained when operating in the individual heating modes.

Effect of Different Irrigating Solutions on Root Canal Dentin Microhardness-A Systematic Review with Meta-Analysis.

The aim of this study was to evaluate the effect of different irrigating solutions as well as their combination and activation modes on root canal dentin microhardness. The protocol was registered in PROSPERO and PRISMA guidelines were followed. The structured question was as follows: "Which type of irrigating solution used in endodontic treatment causes more change in dentin microhardness?" The literature was screened via PubMed, Google Scholar, Scopus, and Science Direct. The last search was carried out in February 2023 with English language restriction. Two reviewers independently performed screening and evaluation of articles. A total of 470 articles were retrieved from all the databases, whereas only 114 articles were selected for full-text analysis. After applying eligibility criteria, 44 studies were evaluated and included in this review. The results showed that with increased contact time with irrigants, dentin microhardness decreases. Increased contact time with sodium hypochlorite (NaOCl) was associated with more reduction in dentin microhardness compared with other irrigants. Other irrigants, with the exception of distilled water, including EDTA, citric acid, herbal irrigants, glycolic acid, phytic acid, etc., in this study significantly decreased dentin microhardness. The maximum reduction in dentin microhardness was seen with 2.5% NaOCl after 15 min of contact time. The use of irrigating solutions alters the chemical composition of dentin, thereby decreasing its microhardness, which affects the clinical performance of endodontically treated teeth.

Mathematical Complexities in Modelling Damage in Spur Gears

Analytical modelling is an effective approach to obtaining a gear dynamic response or vibration pattern for health monitoring and useful life prediction. Many researchers have modelled this response with various fault conditions commonly observed in gears. The outcome of such models provides a good idea about the changes in the dynamic response available between different gear health states. Hence, a catalogue of the responses is currently available, which ought to aid predictions of the health of actual gears by their vibration patterns. However, these analytical models are limited in providing solutions to useful life prediction. This may be because a majority of these models used single fault conditions for modelling and are not valid to predict the remaining life of gears undergoing more than one fault condition. Existing reviews related to gear faults and dynamic modelling can provide an overview of fault modes, methods for modelling and health prediction. However, these reviews are unable to provide the critical similarities and differences in the single-fault dynamic models to ascertain the possibility of developing models under combined fault modes. In this paper, existing analytical models of spur gears are reviewed with their associated challenges to predict the gear health state. Recommendations for establishing more realistic models are made especially in the context of modelling combined faults and their possible impact on gear dynamic response and health prediction.

Feasibility Analysis of Resource Application of Dry Flue Gas Desulfurization Ash in Asphalt Pavement Materials

To verify the feasibility of applying dry flue gas desulfurization ash (DFGDA) to asphalt pavement materials, the asphalt mastic (filler and asphalt composition) prepared by adding different proportions of DFGDA and LSP (limestone powder) into 70# matrix asphalt was studied experimentally. The asphalt mastics were subjected to the penetration test, the softening point test, and the ductility test. Moreover, the rheological properties of asphalt mastic were evaluated with dynamic shear rheometer (DSR) tests and bending beam rheometer (BBR) tests. An interaction ability index C-value based on the Palierne model was proposed to evaluate the interaction ability between DFGDA and asphalt. The influence of DFGDA asphalt on the interaction ability of matrix asphalt was observed and evaluated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that with the increasing proportion of DFGDA, the penetration of asphalt mastic gradually decreased, the softening point increased, and the ductility slightly decreased. At the same temperature, the dynamic shear modulus G* of the asphalt mortar significantly increased with increasing DFGDA content. The incorporation of DFGDA negatively affected the low-temperature plastic deformation resistance of asphalt, but the impact was weakened with the growing DFGDA amount and the powder mastic ratio. The combination mode of DFGDA and matrix asphalt depends on the physical blending, and their interaction ability mainly depends on the miscibility between DFGDA and matrix asphalt. In conclusion, DFGDA can be utilized as a novel filler in asphalt pavement materials.

The combination mode of forest and SVM for power network disaster response failure identification

The damage to power transmission and distribution equipment in different regions is inseparable from the erosion of natural and artificial disasters, affecting the power grid's regular power supply and users' typical power consumption. Therefore, research on failure risk prediction technology for power transmission and distribution equipment under different disasters has increasingly become critical to power grid reliability. Based on the combination mode of forest and Support Vector Machine (SVM), this study proposes a disaster response failure prediction model that considers the time cumulative effect of disaster elements. Based on this model, the failure degree indicators of different disaster elements are constructed by analyzing the relationship between disaster frequency and time. Then, the historical disaster data is used to calculate the index and form a training set with the monitoring data. The binary decision graph transformation method is combined with the adjacent node priority method to obtain the minimum cut set, and the SVM regression method is used to train to get the prediction model. The experimental results show that the effectiveness and accuracy of the proposed method are verified through the analysis of numerical examples and comparison of various techniques. The model's accuracy is 8.63 % higher than that of the traditional disaster prediction model, and the error rate of disaster failure prediction analysis is not more than 0.01.

Study on the segregation effect of pyrite and brass ore particles under combined pendulum vibration

This article uses a combined pendulum mode to study the segregation behavior of spherical particles of pyrite and brass ore with different diameters using the discrete element method. The numerical simulation program includes extensive oscillation tests on binary mixed particles of pyrite and brass ore spherical particles in different steel U-shaped oscillation grooves, different oscillation frequencies, oscillation angles, and particle sizes. The dispersion coefficient γ calculated from the Lacey mixing index M is used to characterize the segregation behavior of binary mixed particles and track the evolution of segregation. Numerical simulation shows that the oscillation frequency is 8 Hz, the oscillation amplitude is 14°, and the dispersion coefficient γ of the first group with protrusions reaches 0.8, which is about 19.4% higher than the dispersion coefficient 0.67 of the first group with light grooves. The dispersion coefficient γ of the second group with added protrusions reached 0.69, which is about 16.95% higher than the dispersion coefficient 0.59 of the second group when using a light groove. The addition of protrusions improved the particle layering effect. The oscillation amplitude is taken as 14°, and the oscillation frequencies are taken as 6Hz, 8Hz, 10Hz, and 12Hz, respectively. As the oscillation frequency increases, collisions between particles become more intense, and the dispersion coefficient γ between particles increases to a certain extent when it changes from 6Hz to 8Hz. Then, as the oscillation frequency increases, the dispersion coefficient γ decreases in severe fluctuations, and the particle stratification effect actually deteriorates. The oscillation frequency is taken as 8Hz, and the oscillation amplitude is taken as 10°, 14°, and 18°, respectively. After the oscillation amplitude increases to 14°, the dispersion coefficient γ of the particles remains basically stable, and changing the oscillation amplitude has almost no effect on the particle stratification effect. The oscillation frequency is 8Hz, and the oscillation amplitude is 14°. When adding protrusions to the steel U-shaped oscillation groove, the average relative errors of both experimental schemes are less than 1%, and the correlation coefficients are close to 1. The data points are very close to the 45° line. It indicates that the experimental data and simulation values have high consistency, and the discrete element method is feasible and reliable as a method for studying mineral particulate matter. The in-depth study of the separation and stratification behavior of ore particles under combined oscillation is of great scientific significance for the development of new combined vibration equipment.

Strain-Based damage model for ductile tearing simulation under combined tensile and shear modes

This paper proposes a strain-based damage model to simulate ductile tearing under combined tensile and shear modes. For tensile mode, the multiaxial fracture strain model depending only on the stress triaxiality is used, determined by analysing smooth bar tensile test and fracture toughness test data. For shear mode, a simple constant fracture strain model is used, determined by analysing smooth bar torsion test and torsion fracture test using a deep surface cracked cylinder specimen. The proposed damage model is applied to simulate circumferential surface cracked pipe made of SUS 304 under combined bending and torsion. Comparison with full-scale surface cracked pipe test data suggests that the use of the combined tensile and shear damage model with the linear interaction rule gives good and conservative prediction results.

An Audio - Visual Virtual Personal Assistant

Current traits in smart assistants and smart home automation are currently attracting the interests of customers and researchers. Speech enabled smart virtual assistants (named smart speakers) offer a wide sort of network orientated services and, in some instances, can connect to smart environments, accordingly improving them with new and effective user interfaces. But, such gadgets also reveal new desires and a few weaknesses. Specially, they constitute faceless and blind assistants, not able to reveal a face, and therefore an emotion, and not able to ‘see’ the person. For this reason, the interaction is impaired and, in a few cases, ineffective. One of the goals of artificial intelligence is the realization of natural talk among humans and machines. In latest years, the dialogue systems, known as interactive conversational systems are the fastest developing vicinity in AI. Many companies have used the dialogue systems technology to set up various sorts of VPAs based on their application areas, including Apple’s Siri, Amazon Alexa, etc. To triumph over such troubles, in this project we combine a number of advance techniques. The proposed Assistant is powerful and resource-efficient, interactive and customizable. We use the multi-modal dialogue structures and screen projection which process two or more combined user input modes, which includes speech, image, video, touch, manual gestures, body movements with the intention to design the NextGeneration of VPAs. The new version of VPAs can be used to increase the interaction between humans and machines by the usage of distinctive technologies, consisting of gesture recognition, image/video recognition, speech recognition, dialogue system, conversational information base, and the overall knowledge base. Furthermore, this VPA device can be utilized in different areas such as education, medical assistance, disabilities systems, home automation and security access control.

Innovation of Course System for Metallurgical Technology Specialty Combining Engineering With Study

With the continuous development of social economy and science and technology, my country's education has also undergone various changes. In order to meet the requirements of the current society, metallurgical technology education in higher vocational colleges must improve the teaching quality from the innovative curriculum system. Vocational colleges themselves are places for cultivating talents for social enterprises, so only by perfecting the curriculum system can the comprehensive ability of students be improved from diversified education. the effective innovation of the curriculum system requires the construction of the higher vocational curriculum system in the mode of combination of work and study. This article mainly focuses on the analysis and research on the innovation of the combined engineering and course system for metallurgical technology majors.

Recent Studies in Metal–Organic Framework‐Based Photocatalysts for Advancing Water Splitting and CO2 Reduction

Combining functional materials with mental–organic frameworks (MOFs) has emerged as a versatile approach to enhance the photocatalytic performance of artificial photocatalysts. This comprehensive review delves into the structural design of MOF‐based composites and highlight the advantages of each structure in water splitting and CO2 reduction. The review begins by discussing the diverse effects of various combination modes on the separation of photogenerated carriers. The synthetic approaches employed for each MOF‐based composite are presented. Subsequently, an in‐depth analysis of the photocatalytic performance of MOF‐based materials in water splitting and CO2 reduction is provided. Finally, the existing challenges and future prospects in the conclusion and outlook section are addressed.