Hydroxide Deposits Research Articles

Carboxylic Acid-Functionalized Cellulose Hydrogel Electrolyte for Dual-Interface Stabilization in Aqueous Zinc-Organic Batteries.

Aqueous zinc batteries (AZBs) are considered one of the most promising candidates for grid-scale energy storage. However, achieving a stable electrode-electrolyte interface remains a challenge for developing high-performance AZBs. Herein, taking the Zn||phenazine (PNZ) system as a prototype, where the proton uptake/removal mechanism dominates in the cathode, a carboxylic acid-functionalized cellulose hydrogel electrolyte is designed to simultaneously solve the issues at both the anode and cathode interfaces. Specifically, the hydrogel electrolyte can not only regulate Zn2+ ions at the Zn anode side but also supply H+ ions at the PNZ cathode side to avoid the unfavored deposition of zinc sulfate hydroxides. Benefiting from the unique one-gel-for-two-electrodes strategy, the dendrite-free and side reaction-suppressed aqueous Zn||PNZ cells are developed with a high specific capacity (311 mAh g-1, 99% utilization of the theoretical capacity) and a long cycle life (over 1500 cycles within 2 months). This study proposes a facile and low-cost electrolyte strategy for stabilizing AZBs.

Synergistic coupling of NiCo-LDH in high-performance supercapacitors via hydrothermal method: Optimal utilization of the potential window

Enhancing the efficiency of layered nickel-cobalt double hydroxides (NiCo-LDH) as electrode materials represented a promising strategy for advancing supercapacitor technology and improving energy storage systems. However, achieving optimal synthesis conditions and addressing the inherent limitations of NiCo-LDH remained critical challenges. In this study, we developed a novel hydrothermal approach to fabricate ultrathin NiCo-LDH nanosheets with a highly porous architecture. In the present study, we have introduced a hydrothermal methodology aimed at the fabrication of ultrathin NiCo-LDH nanosheets characterized by an intricate and highly porous architecture. This innovative approach entailed the simultaneous deposition of nickel and cobalt hydroxides in the presence of ammonium fluoride, a technique that not only streamlined the synthesis process, but also markedly augmented the electrochemical performance of the resultant material. These effects collectively contributed to improved electron transport and structural stability. The optimized NiCo-LDH-18 electrode achieved an exceptional specific capacitance of 2266.6 F g⁻1 and an energy density of 104.8 W h kg⁻1, with a remarkable 93.19 % capacitance retention after 40,000 cycles. Additionally, the potential window of the system closely approximated its theoretical maximum, reaching 96.88 % at a current density of 10 A g⁻1. This refined synthesis strategy offered a significant advancement in supercapacitor performance and stability. By overcoming the inherent drawbacks of traditional supercapacitors, the developed materials provided an effective solution for meeting the growing demand for storage devices with high energy density.

Oxophilic vanadium and deprotonated ruthenium atoms on tungsten carbide with accelerated intermediate migration for high-performance seawater hydrogen evolution

Compared with traditional freshwater electrolysis, the seawater electrolysis process is confronted with low activity and poor stability problems due to the deposition of insoluble hydroxides and corrosion of chloride species; thus, engineering efficient catalysts for seawater electrolysis are extremely desirable but remain challenging. Herein, we have developed an efficient and robust electrocatalyst by engineering oxophilic vanadium and deprotonated ruthenium atoms on tungsten carbide (WC-RuV) as a highly active and anti-poisoning cathode material for superior seawater electrolysis. Benefiting from the high oxophilicity and electron transfer ability of V, the interaction between the OH* generated via water dissociation and Ru sites is weakened, which facilitates the OH* transfer process and consequently attenuates the formation of insoluble hydroxides. Notably, when working in simulated seawater electrolytes, the WC-RuV requires an ultralow overpotential, and the WC-RuV@carbon cloth can maintain high activity and stability even at 200 mA cm−2. The assembled WC-RuV||RuO2 anion exchange membrane (AEM) electrolyzer realizes long-term stability at the current of 100 mA cm−2 and achieves continuous operation powered by commercially available solar panels. This work provides an efficient strategy for modulating the water dissociation process and offers a new perspective for designing high-performance catalysts for the forthcoming application of seawater electrolysis.

Carboxymethyl cellulose enhanced Cr(VI) removal of zero-valent iron via the coating anti-passivation mechanism

Competition for electrons from dissolved oxygen and secondary passivation resulting from the deposition of FeCr hydroxide are two challenges that impede the removal of hexavalent chromium (Cr(VI)) with zero-valent iron (ZVI). In this study, we fabricated micron-sized zero-valent iron modified with carboxymethyl cellulose (CMC-ZVI) via a mechanical ball milling process and demonstrated its improved performance up to eight times for Cr(VI) removal. Owing to the CMC protective film, the inhibition of dissolved oxygen for Cr(VI) removal, aging of ZVI in air, and secondary passivation of ZVI by the deposition of FeCr hydroxides were all inhibited. Even after a week of continuous aging, the CMC-ZVI maintained a stable Cr(VI) removal efficiency of over 50%. The excellent hydrophilicity of CMC enhanced the interaction of CMC-ZVI with water and Cr(VI), thus improving its capacity for Cr(VI) removal. Furthermore, CMC-ZVI not only proficiently reduced and completely removed the high-mobility Cr(VI) from actual electroplating effluent, but also effectively alleviated the inhibition of Cr(VI) removal via CMC-ZVI by aeration and air aging. The efficiency of CMC-ZVI in removing Cr(VI) from actual electroplating effluent was improved by over 41 times compared to pristine ZVI. This advantage has the potential to make the storage and transportation of ZVI more affordable and convenient and increases its potential for practical applications. This study provides an efficient Cr(VI) removal strategy using ZVI for environmental remediation and a strategy for the production of highly reactive, aging-resistant, easily stored, and transported zero-valent iron with the potential for practical applications.

A marine bacteria-inspired electrochemical regulation for continuous uranium extraction from seawater and salt lake brine.

Oceans and salt lakes contain vast amounts of uranium. Uranium recovery from natural water not only copes with radioactive pollution in water but also can sustain the fuel supply for nuclear power. The adsorption-assisted electrochemical processes offer a promising route for efficient uranium extraction. However, competitive hydrogen evolution greatly reduces the extraction capacity and the stability of electrode materials with electrocatalytic activity. In this study, we got inspiration from the biomineralisation of marine bacteria under high salinity and biomimetically regulated the electrochemical process to avoid the undesired deposition of metal hydroxides. The uranium uptake capacity can be increased by more than 20% without extra energy input. In natural seawater, the designed membrane electrode exhibits an impressive extraction capacity of 48.04 mg-U per g-COF within 21 days (2.29 mg-U per g-COF per day). Furthermore, in salt lake brine with much higher salinity, the membrane can extract as much uranium as 75.72 mg-U per g-COF after 32 days (2.37 mg-U per g-COF per day). This study provides a general basis for the performance optimisation of uranium capture electrodes, which is beneficial for sustainable access to nuclear energy sources from natural water systems.

PHOTOCATALYTIC ACTIVITY OF ZnO/TiO2 COMPOSITES IN CIRCULATING CONDITIONS

The development of new efficient photocatalysts is an important task for solving problems related to the purification of water and air from organic pollution. Composite materials based on ZnO and TiO2 exhibit high photocatalytic activity, which makes them promising for this application. In this work, we present the synthesis and study of the photocatalytic activity of ZnO/TiO2 composites obtained by the method of intermediate hydroxide deposition. The synthesis was carried out on the surface of Evonik P25 TiO2 with three different mass ratios of ZnO to TiO2: 1:3, 1:1, and 3:1. The resulting composites were studied by X-ray diffraction (XRD), spectroscopy to determine the optical band gap, and subjected to photocatalytic decomposition under circulating conditions. It was confirmed by XRD that ZnO crystallizes in the wurtzite phase of hexagonal syngony, and TiO2 is contained in the form of two modifications: anatase and rutile. The effect of the mass ratio of ZnO to TiO2 on the optical band gap has been studied. The optical band gap of ZnO/TiO2 composites was determined using the Kubelka-Munk algorithm. For the composites (1)ZnO/TiO2 and (3)ZnO/TiO2, the bandgap was 3.22 eV, and the lowest value (2.99 eV) was obtained for the composite with an equal ratio of ZnO to TiO2 - (2)ZnO/TiO2. The photocatalytic activity of ZnO/TiO2 composites was studied under circulating conditions with congo red dye in the presence of four different composite weights: 0.2, 0.4, 0.6, and 2 g. The maximum efficiency of photocatalytic decomposition of the dye was observed for the composite with an equal ratio of ZnO to TiO2 at a dosage of 2 g of the composite per 0.075 g of dye. The synthesized ZnO/TiO2 composites exhibit high photocatalytic activity, which makes them promising materials for water and air purification from organic pollution. The optimum mass ratio of ZnO to TiO2 for the photocatalytic decomposition of congo red dye is 1:1.

Effect of cobalt hydroxide deposition on the Diffusion-Controlled contribution of cobalt Sulfide-Manganese sulfide electrode for supercapattery

The performance of supercapattery depends on the diffusion rate of the electrolyte ions on the electrode. Metal sulfides have low electrical conductivity and this will affect the active surface reacting with the electrolyte during the charge and discharge processes. In this work, cobalt sulfide-manganese sulfide (CMS) was synthesized via hydrothermal reaction. In order to enhance the channels for the diffusion of electrolyte ions, cobalt hydroxide (COH) was grown on the CMS layer. The structural and morphological of the samples were characterized and the final material was confirmed to be a petal-shaped CMS/COH nanocomposite. CMS/COH showed a higher specific capacity (777.5 C/g at 1 A/g) and a higher diffusion contribution than those of CMS, except for the rate capability. CMS/COH in supercapattery form was designed and the cycle stability was found to reach 72% after 6000 cycle repetitions.

MFe2O4 (M=Mn, co, Ni, Zn) ferrite nanosheets coated flaky FeSiAl composite powder and their magnetism and microwave absorption

Magnetite (MFe2O4, M = Mn, Zn, Ni, Co) nanosheet coated flaky FeSiAl alloy composite powder have been successfully synthesized. The morphology, composition, crystal structures, magnetism and electromagnetic performance of composite powder were studied systematically. Spinel ferrite nanosheet were prepared on the surface of flaky FeSiAl by hydroxide deposition decomposition. This structure will benefit the microwave multiple reflection loss. The saturation magnetization of the composite powder decreased with ferrite coating. The ZnFe2O4 coated composite exhibited higher saturation magnetization while the CoFe2O4 coated composite had the highest coercivity. Owing to the oxide coating, the complex permittivity and dielectric loss of the composite powder were evidently increased while the magnetic loss significantly decreased. Magnetic loss was dominant under 13 GHz and dielectric loss contributed equally as magnetic loss at higher frequency. Therefore, the composite powder attenuate the electromagnetic waves much more efficiently at higher frequency. Our results provide a reference to understand the effect of ferrite nanosheet coating on the magnetism and design the microwave absorption of composite powder materials.

LDH conversion films for active protection of AZ31 Mg alloy

• Zn−Al and Li−Al LDHs with Li-, Mo- and W-based corrosion inhibitors were prepared. • Zn−Al LDH W and Li−Al LDH Li showed the highest corrosion resistance. • XRD, FTIR and XPS analysis confirmed the incorporation of inhibitors. • Active corrosion properties were confirmed by SVET analysis for the Zn−Al LDH W layer. • An inhibition corrosion mechanism is proposed based on several phenomena. Zinc aluminium (Zn-Al) and lithium aluminium (Li-Al) – layered double hydroxides (LDH) coatings with incorporated inhibitors (Li−, Mo− and W−based) were successfully synthesized on AZ31 Mg alloy. Zn−Al LDH W and Li−Al LDH Li showed the highest corrosion resistance and were selected for further evaluation. SEM cross−section examination revealed a bi−layer structure composed of an outer part with loose flakes and a denser inner layer. XRD, FTIR, and XPS analysis confirmed the incorporation of the inhibitors. Post−treatments with corrosion inhibitors containing solutions resulted in the selective dissolution of the most external layer of the LDH coating, reducing the surface roughness, hydrophilicity and paint adhesion of the layers. Active corrosion properties were confirmed by SVET evaluation for the Zn−Al LDH W coating. The proposed active corrosion mechanism involves the ion−exchange of aggressive Cl − ions, deposition of hydroxides and competitive adsorption of W−rich corrosion inhibitors.

Efficacy of removing calcium hydroxide deposits from endodontic instruments prior to sterilization using different cleaning methods

Introduction. Endodontic instruments during root canal treatment come into contact with dentinal debris, irrigation solutions and medication agents, which reminants should be eliminated before sterilization. The aim of the study was to verify the effectiveness of different cleaning methods for removing calcium hydroxide paste residues from the surfaces of the working parts of hand instruments, as well as to propose an effective protocol for cleaning endodontic instruments before sterilization. Material and methods. Forty-two new hand endodontic instruments were used to remove calcium hydroxide paste from the filled canals of extracted teeth. After contamination with medication, they were divided into the four groups and subjected to individual decontamination methods - mechanical, chemical and ultrasonic, as well as a combined protocol. The instruments were then observed under a light microscope. The effectiveness of the methods was evaluated based on the amount of residual matter on the surface of the working parts of the instruments. Results. The combined protocol showed a statistically significant difference in the achieved level of cleanliness compared to mechanical (?2 = 12.00 p < 0.05) and chemical methods (?2 = 12.00 p < 0.05), but there was no statistically significant difference compared to ultrasonic cleaning in disinfectant solution (?2 = 2.4 p > 0.05). By applying combined protocol, instruments with completely clean surfaces were found, as well as the lowest values of contamination at the level of the entire group of instruments (8.33%). Conclusion. The protocol that consisted of mechanical cleaning with a sponge soaked in chlorhexidine gluconate, chemical soaking in sodium hypochlorite, and ultrasonic cleaning in a disinfectant showed the best efficiency in removing calcium hydroxide residues.

Neutron tomography of porous aluminum electrodes used in electrocoagulation of groundwater

In this work, neutron computed tomography (CT) is employed to investigate the dissolution of porous aluminum electrodes during electrocoagulation (EC). Porous electrodes were chosen in efforts to reduce electric power requirements by using larger surface-area electrodes, having both inner and outer surface, for the EC process. Neutron CT allowed 3D reconstruction of the porous electrodes, and image analysis provided the volume of each electrode vs. thickness, which can indicate whether the inner surface is effectively involved in EC reactions. For the anode, the volume decreased uniformly throughout the thickness of the electrode, indicating that both the outer and inner surface participated in electrochemical dissolution, while the volume of the cathode increased uniformly vs. thickness, indicating deposition of material on both the outer and inner surface. The attenuation coefficient vs. thickness, increased for both anode and cathode, indicating surface chemistry changes. For the anode, the attenuation coefficient increased slightly but uniformly, probably due to aluminum oxide formation on the surface of the anode. For the cathode, the attenuation coefficient increased more than for the anode and nonuniformly. The higher increase in the attenuation coefficient for the cathode is due to precipitation of aluminum hydroxide on the electrode surface, which added hydrogen. Image analysis also showed that, although the attenuation coefficient increased throughout the thickness of the electrode, most of the hydroxide deposition occurred on the outer surface. Energy analysis showed that porous electrodes can be used to reduce process energy requirements by as much as 4 times compared to solid electrodes.

Reduced graphene oxide based composite aerogels for energy storage and transportation of methane

Aerogel based on reduced graphene oxide was synthesized using supercritical methods of drying the hydrogel in isopropanol. The synthesis technique involves the deposition of iron hydroxides on graphene layers, then their reduction in supercritical isopropyl alcohol to iron oxides (Fe3O4 and γ-Fe2O3). Results revealed that synthesized adsorbents Graphene aerogel (GA) and GA/Fe show excellent high gravimetric methane adsorption with an achievable capacity of 2.5 g/g and 3.6 g/g, respectively, in the pressure range of 0.5–10 MPa and 298 K, which is more than seven times higher than the requirements established by the US Department of Energy for the gravimetric capacity of a porous material for methane storage. However, at high gravimetric absorption, the volume absorption was 104 m3 (STP)/m3 and 102 m3 (STP)/m3 for (GA) and (GA/Fe), respectively. It should be noted that the performance characteristics of aerogels, in general, are comparable to adsorbents of other classes.

Ex Situ Upgrading of Extra Heavy Oil: The Effect of Pore Shape of Co-Mo/γ-Al2O3 Catalysts

Co-Mo/γ-Al2O3 catalysts with different pore shapes were synthesized for the ex situ upgrading of extra heavy oils by hydrodesulfurization (HDS), hydrodemetallization (HDM), and hydrodeasphaltization (HDA). The catalysts were synthesized using aluminum oxides that were prepared by various methods. It was found that using the product obtained by the thermochemical activation of gibbsite leads to the formation of slit-shaped pores in aluminum oxide, while the application of the hydroxide deposition method by the precipitation of sodium aluminate and nitric acid gives cylindrical pores in aluminum oxide. Co-Mo catalysts synthesized using these two types of pores exhibit different catalytic activities. The catalyst synthesized on a carrier with cylindrical pores exhibited a higher catalytic activity in sulfur, heavy metals, and asphaltenes removal reactions that are synthesized on a carrier with slit-like pores. This is because the presence of cylindrical pores leads to a decrease in diffusion restrictions when removing large molecules of asphaltenes and sulfur-containing and metal-containing compounds.

Fluoride Removal from Drinking Water Using Aluminium Oxide Coated Charcoal – effectiveness of repetitive regenerations

There are many techniques to remove fluoride from drinking water. However, adsorption was found to be very effective and easy to apply. Along with this line, many studies were done to find an effective and affordable fluoride adsorbent. Activated Alumina (AA), Aluminum oxide coated sand (AOCS), pumice (AOCP), bauxite (AOCB) and charcoal (AOCC) were recently investigated. Nevertheless, AOCC found to be more promising for two reasons: it is cheap and can be regenerated. This paper aims to further contribute to feasibility of AOCC for fluoride removal in order to reduce the operation cost. Batch and continuous flow filter runs were conducted AOCC regenerated batch-wise, and used for the next filter run. AOCC was consequently regenerated three times. The results showed a considerable increase in AOCC fluoride adsorption capacity after each regeneration cycle. Characterization of virgin charcoal, virgin AOCC and regenerated AOCC after the first, the second and the third regeneration cycle, showed that virgin charcoal has highest specific surface area and micro porosity. For virgin AOCC and regenerated AOCC after the first, the second regeneration cycle a reduction in the specific surface area occurred, coupled with a reduction of micro porosity. AOCC after third regeneration cycle showed an increase in specific surface area likely due to aluminum hydroxide deposits on re-coated AOCC surface. Most of the pores after the third regeneration cycle were found to be meso pores. This means that, specific surface area alone cannot explain the increase in the AOCC adsorption capacity after regeneration. The paper recommends investigating the fluoride removal mechanism onto AOCC in order to produce affordable fluoride removal material from drinking water.

The Influence of Wetting Agent and Type of Nozzle on Copper Hydroxide Deposit on Sugar Beet Leaves (Beta vulgaris L.)

Protective fungicides are sensitive to environmental conditions such as rainfall and solar radiation. Therefore, it is important to prolong the biological activity and fungicide resistance to the above-mentioned factors that can be achieved by adding a wetting agent to the working solution. Additionally, the quality and efficiency of preventive contact fungicides significantly depend on the application technique. Thus, it is important to make the right choice of the nozzles and adjust the working parameters of the treatment. The aim of this work is to determine the influence of a wetting agent and type of nozzle on copper hydroxide (2 L ha−2) deposits on sugar beet leaves. Experiments are set up under laboratory and field conditions. A pinole-based wetting agent is applied at three rates (0.3, 0.6, and 1.0 L ha−1) and two types of nozzles are used (standard with flat jet and modern turbo-drop twin-jet). A brilliant blue tracer is added to a working solution to enable the measurement of copper hydroxide deposits. The deposit amount is recorded before and after the rain simulation (15 L m−2) with a spectrophotometer light beam. In order to ensure the timeliness of the application of fungicides, remote sensing of vegetative indices is used as an indicator of disease occurrence. The results indicated an increase in copper hydroxide deposits with the increase in wetting agent rates for both types of nozzles and in both laboratory and field experiments. Moreover, when applying the copper hydroxide mixtures with modern turbo drop nozzles, the increase in copper hydroxide deposit is significant, compared to the standard nozzles.

Efficiency definition of the deposition process of electrochromic Ni(OH)2-PVA films formed on a metal substrate from concentrated solutions

Electrochemical devices based on nickel hydroxide electrodes are used in different areas. The main ones are chemical current sources, variable transparency “smart” windows, devices for carrying out electrocatalytic reactions, sensors for determining various substances. In this regard, methods of nickel hydroxide synthesis are of great interest, especially those that allow forming nickel hydroxide directly on the surface of electrodes. One of these methods is electrochemical deposition with cathodic current polarization. The available information on nickel hydroxide synthesis from nickel solutions was considered. It was shown that the available data mainly covered information on dilute solutions from 0.01 to 0.25 mol/L Ni(NO3)2. In addition, no comparison was found in the literature for the efficiency of the cathodic formation of Ni(OH)2 at different concentrations of nickel nitrate. To eliminate the lack of information, the dependence of the current efficiency on the concentration of nickel nitrate in the electrodeposition solution was determined at a constant cathode current density of 0.625 mA/cm2. The resulting dependence decreased nonlinearly with increasing concentration. The nickel hydroxide deposit formed in this case had an X-ray amorphous structure, and it depended little on the Ni(NO3)2 concentration. In addition, the current efficiency reached zero at concentrations of 1.5 mol/L Ni(NO3)2 and higher. However, with polyvinyl alcohol in the solution and at Ni(NO3)2 concentrations of 1.5 and 2 mol/L, electrochemically and electrochromically active Ni(OH)2 films were deposited. The current efficiency calculated indirectly for 1.5 and 2 mol/L Ni(NO3)2 solutions was 3.2 and 2.3 %, respectively. Thus, it was concluded that polyvinyl alcohol affected the mechanism of nickel hydroxide electrodeposition from aqueous solutions of nickel nitrate.

Comparative Characteristics of Xerogels Based on Zirconium Dioxide Obtained by the Method of Joint Deposition of Hydroxides in a Volume and a Microreactor with Counter Swirled Flows

Comparative Characteristics of Xerogels Based on Zirconium Dioxide Obtained by the Method of Joint Deposition of Hydroxides in a Volume and a Microreactor with Counter Swirled Flows

Design of a higher positive valence band in g-C3N4 photocatalyst for enhanced photocatalytic activity by copper hydroxide deposition

ABSTRACT The graphitic carbon nitride/copper hydroxide photocatalyst, which achieved ∼15.8-fold enhanced visible-light photocatalytic performance for pollutant degradation compared to origin g-C3N4, was synthesised by chemical deposition strategy. The experimental results show that Cu2+ ions in Cu(OH)2 interact with electron-rich N atoms in g-C3N4. The stronger interaction promotes the change of the local electric field in g-C3N4/Cu(OH)2 to obtain a more positive valence band, which can generate strongly oxidised photogenerated holes. This photogenerated holes played a dominant role in pollutant degradation. The present work may provide a promising approach to the fabrication of other efficient photocatalyst.

Multicomponent architectured battery-type flexible yarns for high-performance wearable supercapatteries

Rational design of light weight, flexible and wearable yarn-type electrodes with selectively designed battery-type materials has attracted a promising research interest for the development of high-performance miniatured energy storage devices. However, the relatively lower energy storage performance caused by poor mass loading of existing fiber/yarn-based devices limits their practical applicability in a wide range. Herein, an unique plaiting approach is demonstrated to design flexible and wearable yarn-type supercapatteries (YSCs) with high electrochemical performance. With ubiquitous polyester fabric fibers (PFs) in a plaiting form, PFs are converted into highly conductive plaited PFs via dual layered metallization with superior surface roughness. Upon deposition of carbon nanotubes and nickel cobalt double hydroxides on metallized PFs, an efficient battery-type electrode is designed, which exhibits a high specific capacity of 162.8 mAh g−1 with an excellent cycling stability of 93.3% in alkaline electrolyte. The two-electrode system-based solid-state YSCs are further assembled using multicomponent architectured battery-type and capacitive-type activated carbon electrodes, which enables a high potential of 1.55 V with superior energy and power densities (30.49 Wh kg−1 and 1137.26 W kg−1), respectively. By capitalizing high energy storage, the solar charging-based YSC is practically examined to be able to energize various wearable electronics.

Investigation of a modified hydraulic calcium silicate-based material - Bio-C Pulpo.

This study evaluated the physicochemical, biological, and antimicrobial properties of a new hydraulic calcium silicate-based modified material, and compared it with MTA Repair HP and MTA Angelus. The materials were assessed regarding color luminosity (L), color change, radiopacity, setting time, and ISO 6876:2012 linear flow. Volumetric filling and volume change were evaluated using microcomputed-tomography (µCT). Chemical characterization after 28 days in Hank's Balanced Salt Solution (HBSS) and pH analysis were also assessed. Biological characterization of cytotoxicity and microbiological assessment were also undertaken. Shapiro-Wilk, ANOVA, Levene and post hoc analyses with Bonferroni correction were performed, adopting a 5% significance level (p <0.05). Bio-C Pulpo exhibited the highest L values after 90 days. All tested materials demonstrated color change during the analyses, and had radiopacity above 5 mm Al. MTA Repair HP set faster than Bio-C Pulpo, whereas the latter had the highest linear flow. MTA Repair HP had the highest volumetric filling in µCT analysis. Bio-C Pulpo showed the highest alkalinity during all tested periods, and the highest volumetric loss (above 9%), in comparison with MTA Repair HP and MTA Angelus. Bio-C Pulpo did not form calcium hydroxide after hydration. MTA Repair HP demonstrated the highest cytocompatibility, and Bio-C Pulpo, the highest cytotoxicity. No inhibition halos were observed for any material, and similar higher turbidity values were seen after direct contact. Composition additives used in Bio-C Pulpo modified its properties, and both the absence of calcium hydroxide deposition after hydration, and the related cytotoxicity of this material are of particular concern.