Large Capacity Research Articles

Performance analysis on a hybrid system of wind, photovoltaic, thermal, storage, CO2 sequestration and space heating

The combined heat and power generation (CHP) isan efficient and economical solution to the intermittency and instability faced by renewable energy power and however, the heat-power coupling lowers its regulation depth. Thermal energy storage is a valid measure to solve the above problem, however, the major bottleneck is lack of thermal energy storage ways with large capacity, high efficiency, low cost and longtime simultaneously. Here, a novel hybrid system of wind-photovoltaic-thermal-storage-CO2 sequestration-space heating is proposed, which can store thermal energy and sequestrate CO2 in saline aquifer simultaneously. The results show heat extraction power, energy storage capacity, energy storage density and thermal recovery efficiency for the hybrid system are respectively 6391.14 kW, 66263.36 GJ, 23276.37 kJ/m3 and 81.17 %. The hybrid system extends the adjustable range of CHP from 200 MW to 700 MW through thermal energy storage and heat-power decoupling, thus accommodating more renewable energy power. The amount of sequestrated CO2 captured from exhaust gas of thermal power station is 2,306,880 tons, equivalent to 854,400 tons of standard coal in terms of carbon dioxide emissions. In addition, the repeated injection and extraction of working gas in the hybrid system accelerates CO2 solubility in saline aquifer.

Photocatalytic performance with electrochemical effects for ZnO/graphene quantum dots/CdSe nanocomposite toward ciprofloxacin antibiotics and paracetamol degradation under visible light

There has been significant interest in the advancement of photocatalytic materials that can respond to visible light, in order to fulfill the needs of conserving energy and reducing emissions. Photocatalysis is a method employed to eliminate organic contaminants from wastewater. This study examined the effectiveness of graphene quantum dots (GQDs), zinc oxide/graphene quantum dots (ZnO/GQDs), and zinc oxide/graphene quantum dots/cadmium selenide (ZnO/GQDs/CdSe) as catalyst powders in decomposing Paracetamol and Ciprofloxacin antibiotics when exposed to visible light. The ZnO/GQDs/CdSe composite was synthesized using calcination at a temperature of 400°C for a duration of 2 hours. The studies demonstrated that ZnO/GQDs/CdSe exhibited exceptional catalytic efficiency in the photodegradation of Paracetamol and Ciprofloxacin antibiotic, surpassing other catalysts with degradation rates of 99.2% and 99.9%, respectively. The ZnO/GQDs/CdSe composite can be recycled up to 5 times without experiencing any additional damage. Our findings indicate that the combination of GQDs, ZnO, and CdSe forms a photocatalytic system that follows the Z-scheme heterojunction model. This system demonstrates enhanced efficiency in transferring photogenerated electron-hole pairs and possesses a large redox capacity. These conclusions are supported by the results of radical trapping tests.

A K2C2O4/nano-CaCO3 dual-templated method to prepare rich nitrogen-doped hierarchical porous carbon with excellent lithium storage performance

Three-dimensional interconnected porous carbon with diverse guest element doping is considered one of the most promising anode materials in lithium-ion batteries (LIBs) owing to their large lithium storage capacity and the acceleration effects on the electrochemical kinetics. However, the regulation of desirable pore structure and guest element amount and species for high energy density and stable cycling performance is still challenging. Herein, sucrose-based hierarchical N-doped porous carbon (SHC-750) is prepared via a facile one-step carbonization/activation process at 750 °C for 1 h. The K2C2O4 and nano-CaCO3 are employed as the dual activating-agent/template, and the urea is used as an N source. Benefiting from the hierarchical porous structure, abundant defects, and high amount of N/O-containing functional groups with a multi-chemical state, SHC-750 delivers an excellent reversible specific capacity (1051.2 mAh/g at 0.1 A/g and) and great cycling stability. Moreover, SHC-750 exhibits fast lithium ions diffusion kinetics, which is attributed to the special ordered and hierarchical pore structure. This work provides a new pathway for the preparation and application of 3D interconnected porous carbon materials in the field of electrodes.

Storage capacity estimates and site conditions of potential locations for offshore-wind powered carbon dioxide removal and carbon sequestration in ocean basalt

Negative emission technologies (NETs) are considered essential to keep global warming below 2 °C. Situating wind-powered carbon dioxide removal (CDR) devices offshore and injecting carbon dioxide (CO2) into deep-water sub-seafloor basalt aquifers has the potential to offer large CO2 removal capacity. It also avoids land and water-use competition and provides additional low-risk protections against post-injection leakage compared to terrestrial CO2 storage. This paper seeks to identify locations where offshore wind and potential basalt storage locations exist within close proximity to one another around the globe. A global mean wind power density map at 150 m height was computed using 30 years (1986–2016) of ERA5 hourly wind speed reanalysis data. Offshore regions with mean wind speed greater than 8 m/s were identified. Offshore regions with basalt aquifers along seismic or aseismic ridges which provide potential CO2 storage sites were identified and selected based on sediment thickness, age, and distance from plate boundaries. Four scenarios were constructed to capture a range of constraints with implications for technical, economic and regulatory difficulties. For each scenario, eligible regions for CO2 injection were filled by regularly spaced grid points and the distance to the nearest eligible wind resource was calculated for each point to identify the most promising configurations. Total available storage capacity within reach of wind resources was estimated to be between 4,300Gt and 196,000Gt depending on both uncertainties in porosity and other imposed constraints; even the most conservative estimates represent enormous capacity compared to global targets for negative emissions technologies. Typically, the best areas were found close to the poles due to the greater prevalence of good wind resources in those areas. Site-specific properties such as water depth and distance from shore are computed for the identified locations in order to characterize the conditions in which such locations are typically found.

Fast impedance measurement method for large capacity batteries using chirp and filtered pseudo-random binary sequence

Fast impedance measurement with well-constructed excitation signals is crucial for battery internal states analysis and faults diagnosis. The pseudo-random binary sequence (PRBS) is a promising time-efficient excitation signal, but it lacks power content in the low-frequency range and is susceptible to high-frequency harmonics beyond the measurement limits, especially for square large-capacity batteries. Motivated by this, this paper proposes a novel parallel-connected signal derived from filtered PRBS and chirp sequence to boost low-frequency components while mitigating high-frequency effects. Meanwhile, to enhance accuracy in measuring square large-capacity batteries with low impedance, the paper introduces a differential amplification circuit to improve voltage response robustness against noise. Experimental results confirm the effectiveness of this method, achieving precise impedance measurements across the 0.1 Hz–1000 Hz range in just 10.24 s. With different states of charges, temperatures, and battery types, errors of the measurement are below 3.67 %.

Configuration Design and Size Optimization of a High-Precision Novel Parallel Pointing Mechanism Based on Interference Separation

AbstractPointing mechanism is widely used in aerospace field, and its pointing accuracy and stability have high requirements. The pointing mechanism will be affected by external interference when it works. In order to eliminate the impact of interference forces on the output accuracy of the mechanism, firstly, this paper proposes a design method for high-precision pointing mechanisms based on interference separation, aiming at the high-precision pointing requirements of pointing mechanisms. Based on the screw theory, a synthesis method for inner compensation mechanisms has been proposed. And a new type of double-layer parallel mechanism has been designed to compensate for interference forces. Then, the kinematics and dynamics of the mechanism are carried out. An evaluation index for compensating external interference forces is proposed. The interference compensation analysis is conducted for the pointing mechanism. The correctness of the proposed interference force compensation coefficient is verified. Finally, in order to find the optimal solution for the workspace and interference force compensation coefficient of the pointing mechanism, multi-objective optimization design of the structural parameters of the mechanism was carried out based on the particle swarm optimization algorithm. This provides a theoretical basis for the prototype design of the subsequent double-layer parallel mechanism. This double-layer parallel mechanism combines the advantages of large load-bearing capacity, large workspace, and high output accuracy. It can be better applied in the aerospace field where high-precision pointing and force interference compensation are integrated.

Thermal studies on cryocooler thermal masses from 4 K to 300 K for MRI applications

AbstractGifford–McMahon (GM) cryocoolers are pivotal for maintaining the temperature of MRI magnets, necessitating regular servicing for optimal performance and longevity. This study explores the geometric dimensions and shapes of superconducting magnets utilized in MRI for system cooling. The investigation demonstrates that warm-up time is contingent on heat capacity rather than geometric shapes. As a result, the design of magnets can be customized to specific shapes and sizes in accordance with favorable conditions, given that warm-up time is solely dependent on heat capacity. The primary focus is to deliberately prolong the warm-up time of the magnet relative to the GM cryocooler, consequently minimizing service intervals. Laboratory evaluations explore the use of thermal masses equivalent to MRI magnets, employing typical materials such as copper and aluminum. These masses are cooled to 4 K and then subjected to different heating powers to evaluate warm-up characteristics. Various configurations and shapes of thermal masses are numerically studied for warm-up analysis. Comparative assessments between experimental results and simulations reveal that, for cylindrical thermal masses, 80 W heating power facilitates a 76% reduction in warm-up time compared to 20 W heating across all cases. In the exploration of different geometric thermal masses, aluminum demonstrates a remarkable 35% decrease in warm-up time compared to copper. A noteworthy finding emerges, indicating that warm-up time is contingent on heat capacity rather than geometric shapes. These insights hold substantial relevance, particularly in systems with large thermal capacities, such as superconducting magnets. The study contributes valuable knowledge to the optimization of GM cryocoolers for enhanced MRI magnet performance and extended operational life.

Shake table testing of a seismic isolation system for lightweight structures

AbstractThe implementation of seismic isolation in lightweight structures, such as houses, is limited, except for Japan, where nearly 5000 houses are seismically isolated with highly engineered systems. The use of such systems in countries of growing economies is prohibitive due to their cost, difficulties in locally fabricating components, and incompatibility with local construction practices. Previous studies on low‐cost isolation systems showed that isolation devices with rolling rather than sliding elements are more suitable for lightweight structures. A low‐cost isolation system based on a deformable rolling bearing developed at the University at Buffalo has simple components that can be easily manufactured, has a large displacement capacity, and features a fail‐safe mechanism. The bearing is composed of one flat and one concave concrete plate and a rubber rolling ball. This paper presents the results of shake table testing of half‐length scale versions of prototype houses and small bridges equipped with this deformable rolling isolation system in three‐directional seismic excitation. The results showed that deformable rolling bearings provide significant seismic protection of lightweight structures against strong ground motions, which in the testing reached a maximum peak ground velocity of 1.2 m/s in the test scale and a peak ground acceleration of 4 g in the horizontal direction and up to 1 g in the vertical direction. The isolation system was particularly effective in the horizontal direction, whereas it did not provide any vertical isolation. The tests included cases of extreme response, which included vertical impact within the bearing's components and uplift of the isolated structure.

High-Na-Content Birnessite via P'3-Stacking with Tunable Active Facets for Advanced Aqueous Sodium-Ion Batteries.

Layered Na-birnessites are promising cathode materials for aqueous sodium-ion batteries due to their high theoretical capacity, low cost, and environmental benignity. However, the general O'3 Na-birnessites possess low Na content and dominant inactive {001} exposed facets, which compromise their Na storage capability and cycling stability. Herein, we develop a high-Na-content P'3-Na0.71MnO2·0.15H2O with highly enriched {010} active facets by a hydrothermal conversion method. In comparison with the O'3 Na-birnessite, the P'3 Na-birnessite with a high ratio of {010}/{001} exposed facets provides greatly increased open channels for Na+ diffusion, while the P'3 stacking affords a lower Na+ diffusion barrier, resulting in improved electrode kinetics with a large specific capacity of 176 mAh g-1 at 0.2 A g-1. More importantly, the P'3 Na-birnessite manifests solo Na+ intercalation/deintercalation with extraordinary cycling stability in an aqueous electrolyte, achieving 90.5% capacity retention after 60,000 cycles. When coupled with the NaTi2(PO4)3 anode, the P'3 Na-birnessite-based full cell delivers both high energy density and long cycle life, demonstrating the potential application in aqueous sodium-ion batteries. This study demonstrates an efficient method to prepare high-Na-content P'3 birnessite with tunable exposed facets and provides important insights into developing highly stable layered cathodes for sustainable aqueous sodium-ion batteries.

Phytic Acid Functionalized Hierarchical Porous Metal-Organic Framework Microspheres for Efficient Extraction of Uranium from Seawater.

Uranium is a critical resource in the development of nuclear energy, and its extraction from natural seawater has been identified as a potential solution to address uranium resource shortages. In this study, hierarchical meso-/micro- porous metal-organic framework functionalized with phytic acid (PA) microspheres (denoted H-UiO-66-PA) are rationally synthesized for efficient uranium extraction. This unique design allowed for a large adsorption capacity and fast adsorption kinetics, making it a promising material for uranium extraction. Due to the hierarchically porous structure, H-UiO-66-NH2 materials not only provide more sites for grafting PA, and thus enhance the adsorption capacity, but also facilitate the rapid diffusion of uranyl ions which can quickly and effectively access the interior of the H-UiO-66-PA adsorbent. Therefore, the obtained H-UiO-66-PA can achieve an impressive absorption efficiency of 6.76mgg-1 in actual seawater within 15 days. Meanwhile, the H-UiO-66-PA possesses a good adsorption capacity for uranyl ions in the five adsorption/desorption cycles. This work proposes a feasible strategy for constructing functional hierarchical porous MOFs for uranium removal.

Dual Redox Reactions of Silver Hexacyanoferrate Prussian Blue Analogue Enable Superior Electrochemical Performance for Zinc‐ion Storage**

AbstractPrussian blue analogues (PBAs) have been employed as host materials of aqueous zinc‐ion batteries (ZIBs), however, they suffer from low capacity and poor cycling stability due to limited electron transfer and the presence of interstitial water in PBAs. Herein, a vacancy and water‐free silver hexacyanoferrate K0.95Ag3.05Fe(CN)6 (AgHCF‐3) was synthesized by adjusting the ratio of K and Ag in the framework. It offers nearly four electrons involving two sequential redox reactions, namely, Fe3+/Fe2+ and Ag+/Ag0, to deliver a large capacity of 179.6 mAh g−1 at 20 mA g−1 with Coulomb efficiency of ~100 %. The Zn//AgHCF‐3 cell delivers an estimated energy density of 200 Wh kg−1, surpassing reported PBAs‐based ZIBs. The formation of Ag0 in the cycling process merits favorable rate performance of AgHCF‐3 (156.4 mAh g−1 at 200 mA g−1 with 80.3 % capacity retention after 100 cycles). This investigation paves new pathways for high‐capacity PBA cathodes.

Half‐Heusler Alloy CoMnZ (Z = Sb/Sn): Electrode Material for Lithium‐Ion Batteries

ABSTRACTHeusler alloys (HAs) are a well‐known family of compounds generating promising interest due to their robust structure, ease of tailoring their unique properties, and potential applications. The investigations in the direction of the electrochemical performance of these materials as electrodes for rechargeable lithium‐ion batteries (LIBs) have been established theoretically and experimentally. Alloying of alkali metal ions into half‐HAs unit cells can be another route to improve LIBs performance. This work presents our investigations on thermodynamically stable half‐HAs CoMnZ (Z: Sb/Sn) as electrode materials for rechargeable LIBs using the first‐principle calculations based on the density functional theory. The negative formation energies validate the thermodynamic stability of the alloys considered in this study. With increasing Li doping, a structural change from cubic to tetragonal and orthorhombic phase is observed in the host structure, and upon full lithiation (LiMnZ), a cubic structure is attained. The band structure calculations of the host structure and its lithiated phase indicate a metallic nature in these alloys. The calculations are also performed to investigate the structural stability of parent alloys and corresponding lithiated phases. We calculated a storage capacity of around 14.5 Ah/kg for 0.125 atomic fraction of Li atoms, which is increased by nearly 10 times upon full lithiation. A maximum open circuit voltage of around 9.8 V is calculated for Li0.125Co0.875MnSb and CoLi0.125Mn0.875Sb. Thus, all these remarkable results suggest that these intermetallic compounds have a strong potential as the cathode material for LIBs with a robust life and a large capacity.

Behavior of the Electricity and Gas Grids When Injecting Synthetic Natural Gas Produced with Electricity Surplus of Rooftop PVs

Distributed generation and sector coupling are key factors for economic decarbonization. Because gas networks have a large storage capacity, they have attracted the attention of power engineers to use them to increase the flexibility and security of supply in the presence of renewable and distributed energy resources. This paper makes the first attempt to integrate the electricity and gas systems to fill available gas storage facilities with synthetic natural gas on a large scale. This synthetic natural gas can then be used to operate gas turbines and to compensate for the fluctuating production of renewable energy sources. The LINK-holistic architecture, which integrates renewable and distributed energy resources, is used in this work. It facilitates sector coupling, which means power-to-gas and gas-to-power, throughout the entire power grid and at the customer level. This work is limited to investigating the power-to-gas process at the prosumer level. The electricity surplus of rooftop PVs is used to produce synthetic natural gas, fed into the gas grid after covering the local gas load. The behaviors of the electricity and gas grids are investigated. Results show that electricity prosumers may also become prosumers of synthetic natural gas. The current unidirectional gas grids should be upgraded with compressors at pressure reduction groups to turn them bidirectional, allowing synthetic natural gas storage in the existing large gas storage appliances after considering the pipes’ linepack effect. The proposed solution could make it possible to fill the underground storage plants in summer, when the electricity and synthetic natural gas production exceed electrical and gas demand, respectively.

Progress in the application of silicon-based materials in lithium-ion batteries anodes

From the battery that powers the remote control to the battery that powers electric cars, lithium-ion batteries (LIBs) are a crucial component of contemporary energy storage. The large theoretical capacity of silicon anodes provides significant benefits inside LIBs. However, the main issue with the conventional silicon bulk anode is its considerable volume expansion, which forms an unstable Solid Electrolyte Interface (SEI) layer during the charge and discharge process and severely reduces battery performance and lifespan. Therefore, to solve these issues, researchers have explored multiple improved silicon anodes, three of which are mentioned in this essay. Firstly, the researchers delve into the usage of nanotechnology. When manipulating silicon particles at the nano-scale, the nano-silicon can mitigate the volume expansion, improving the reaction kinetics. Then, a composite of carbon and silicon is proposed, combining silicon's high capacitance and carbon's high conductivity. After that is the silicon-metal composite, which utilizes metals' mechanical strength and conductivity to stabilize Si anodes further and improve thermal stability. Overall, the significance of this study lies in the exploration of the application of silicon anodes in LIBs, highlighting the potential of these composite materials and advanced technology, which may help guide the future exploration of better silicon anodes.

Experimental investigation on thermodynamic and environmental performance of a novel ocean thermal energy conversion (OTEC)-Air conditioning (AC) system

In the field of isolated island energy supply, the OTEC system is considered promising due to its large storage capacity, and pollution-free characteristics. To improve energy efficiency, polygeneration systems have gradually become a research hotspot for their low cost and high return features. In this context, a novel Ocean Thermal Energy Conversion system integrated with an air conditioning unit (OTEC-AC) is introduced, demonstrating capabilities in electricity, cooling capacity, and fresh water production by experiments. The effects of various flow rates and temperatures of the heat and cold sources, along with the air-conditioning system water flow rate on the system performance is explored. Besides, the overall performance of the OTEC-AC is compared with four representative OTEC models. The results indicate that there is a threshold for the influence of cold and heat source flow rate on the performance of power generation system. The OTEC-AC system shows a highest net power of 132.6 W, cooling capacity of 2.14 kW, condensate production of 3.24 kg/h, and achieves a system exergy efficiency and CO2 reduction of 34.7 % and 5801 kg/year, respectively. The annual CO2 reduction per kilowatt of installed capacity of the system is increased by 135.6 %, compared with the conventional OTEC system.

Study on the hard carbon anode from different precursors for sodium ion batteries

Sodium-ion batteries (SIBs) are commonly utilized in power storage applications. It can be used as alternatives to lithium-ion batteries. Nevertheless, the development of SIBs is restricted by anode materials due to the high redox potential and large irreversible capacity. As a common anode material of SIBs, hard carbon exhibits a substantial interlayer spacing and a excellent reversible specific capacity, while the properties and costs are affected by its precursors. This article mainly describes the sodium storage principle of hard carbon and compares the performances as well as modification methods of hard carbon produced from various precursors. The hard carbon basing on coal has the advantages of low cost due to the abundant reserves of coal precursors and low redox potential. Biomass-based hard carbon has natural pores which can assist the sodium ions transport in carbon materials. We further explain the effects of modification strategies such as heteroatom doping, activation treatment and mechanical ball milling on electrochemical properties of hard carbon. Finally, this paper recognizes the existing problems and corresponding solutions of materials made of hard carbon and looks forward to the future research focus on hard carbon materials.

Predictive Factors for Clean Intermittent Catheterization after Intravesical OnabotulinumtoxinA Injections in Women with Overactive Bladder: a Danish Retrospective Cohort Study.

We aimed to evaluate the clean intermittent catheterization (CIC) rate in women undergoing their first OnabotulinumtoxinA (BTX-A) treatment and to investigate factors predictive of initiating CIC. This was a retrospective cohort of women, who had their first BTX-A treatment for symptoms of overactive bladder (OAB) syndrome, with a pretreatment urodynamic study (UDS). We reviewed demographic, medical and gynecological history, UDS, pretreatment bladder diaries, objective examinations, BTX-A treatment details, and post-void residual (PVR) reports in the electronic medical record. Botox® Allergan 100 International Units were injected into the detrusor at 10-20 sites. Statistical analyses included univariate and multivariate logistic regression analyses. We included 397 women. Median age was 68 (Q1-Q3: 54-76) years. CIC rate was 8.6% (n = 34) following the first BTX-A treatment. Urgency urinary incontinence (UUI) reduced the risk of undergoing CIC (OR 0.30, 95% CI 0.09-0.97). A bladder capacity of 500ml or greater in the bladder diary increased the risk of CIC (OR 2.46, 95% CI 1.06-5.70), whereas reported leakages were associated with a decreased risk of CIC (OR 0.24, 95% CI 0.10-0.57). Multivariate logistic regression analysis showed that anterior colporrhaphy (OR 3.71, 95% CI 1.52-9.06) and 10-ml increments in median maximum cystometric capacity (OR 1.03, 95% CI 1.00-1.06) predicted CIC, whereas UUI was a protective factor for CIC (OR 0.23, 95% CI 0.07-0.79). A history of anterior colporrhaphy, large bladder capacity, and absence of incontinence episodes in bladder diary or UDS were risk factors for CIC after the first BTX-A treatment.

Multi‐operating characteristic analysis and loss optimization of novel large capacity high‐speed permanent magnet generator

AbstractRecently, the development trend of large capacity generator has gradually shifted from electrical excitation generator to permanent magnet generator (PMG). As a result, the large capacity high‐speed permanent magnet generator (HSPMG) with high power density and high efficiency have received widespread attention. This paper aims to analyse the loss optimization of novel large capacity HSPMG under multi‐operating conditions. In terms of the parameter requirements, a 2.5 MW and 7000 rpm HSPMG is designed. To verify the accuracy of simulation model and the rationality of generator design, the output characteristics of large capacity HSPMG which has been combined with prototype experimental data are calculated under both no‐load and load conditions. Based on the load power characteristics of large capacity HSPMG, the optimization range of the magnetization angle under multi‐operating conditions is explored. By analysing the no‐load back electromotive force (EMF) and loss characteristics of large capacity HSPMG, the optimal magnetization angle that corresponds to the minimum loss under three conditions is obtained. The correctness of the analysis and optimization method is verified by comparing the loss distribution and electromagnetic results before and after the optimization. The research results provide a reference for the multi‐operating characteristics analysis and loss optimization of large capacity HSPMG.

Investigations of Mechanisms Leading to Capacity Differences in Li/Na/K-Ion Batteries with Conversion-Type Transition-Metal Sulfides Anodes.

Conversion-type transition-metal sulfides (CT-TMSs) have been extensively studied as the anode of Li/Na/K-ion batteries due to their high theoretical capacity. An issue with the use of the material in the battery is that a large capacity difference is commonly observed. However, the underlying mechanism leading to the problem is still unknown. Here, the large capacity difference mechanisms of CT-TMSs anodes in the Li/Na/K-ion storage are elucidated, which arises from the difference in conversion degree and size of conversion products. Specifically, the increase in ionic radius will cause the increase in insertion-reaction ion diffuse energy barrier and conversion-reaction Gibbs free energies of phase transformation to decrease reaction kinetics, which causes a decrease in conversion degree and an increase in size of conversion products, thus leading to reduction in capacity. The increase in size and the decrease in the amount of conversion products inevitably reduce the amount of spin-polarized electrons injection into Fe and corresponding ions storage amount into sulfides during the ion-electron decoupling storage, thus reducing the capacity. The research clarifies the capacity difference mechanisms of CT-TMSs anodes in Li/Na/K storage, providing valuable insights for designing Li/Na/K storage high-capacity anodes.

In situ dual-utilize of ZnCl2 for preparation of ZIF-8 functionalized biomass-based porous carbon for adsorption removal of volatile organic compounds

In this study, ZnCl2 was successfully dual-used for the chemical activation of biomass-based activated carbon (BAC) and ZIF-8 synthesis to prepare the functionalized porous carbon composite PC-Z/W. The findings indicated that the chemical activator ZnCl2 be directly recycled for the synthesis of ZIF-8 on BAC. The ZIF-8 functionalization provided the PC-Z/W composites with a well-developed porous structure and rich N- and O-containing surface functional groups, which enabled the PC-Z/W to exhibit superior adsorption properties (large adsorption capacity, temp adaptability, and competitive adsorption with water) for low-concentration gaseous pollutants. The PC-Z/W(P1000) exhibited the best adsorption performance for toluene, with a saturation adsorption capacity (qs) of 277 mg/g at 25 °C and retained 70 % of qs (192 mg/g) at 80 °C. It also has exceptional adsorption capabilities for acetone (qs = 170 mg/g) and ethyl acetate (qs = 227 mg/g), enabling it to show superior multi-component adsorption behavior and effective competition with water. In addition to VOCs, PC-Z/W is also noteworthy for the adsorption of inorganic substances like SO2 (203 mg/g) and CO2 (4.65 mmol/g), greatly broadening its application prospects.