Magnesium Hydroxide Carbonate Research Articles

Catalytic hydrogenation of magnesite to methane and magnesium oxide using magnesium carbonate hydroxide as model compound

The hydrogenation of magnesite to CH4 and MgO offers a powerful approach for CO2 direct utilization. To deepen the understanding of the reaction mechanisms, (Mg5(CO3)4(OH)2(H2O)4 was selected as a model compound to gain insights into carbonate hydrogenation. A novel Ni/Fe/ZrO2 catalyst with ferromagnetic properties was employed to facilitate the magnetic separation of the catalyst from the solid products. Thermodynamic simulation and experiments were conducted to address key issues such as gas evolution during catalytic hydrogenation, the effects of catalyst on CH4 selectivity, and the separation of solid products and catalyst. The results indicate that lower temperatures favor CH4 formation, whereas higher temperatures favor CO formation. Increasing Ni loading can enhance the CH4 selectivity. With the presence of 10Ni/Fe/ZrO2 catalyst, 100% CH4 selectivity can be achieved at 300 °C. Moreover, 10Ni/Fe/ZrO2 catalyst exhibits high magnetic responsiveness, facilitating the solid separation and the recycle of the catalyst.

1D hollow tubular/2D nanosheet hybrid dimensional porous carbon prepared by one-step carbonization using natural minerals as templates for supercapacitors.

The reasonable construction of one-dimensional (1D)/two-dimensional (2D) hybrid dimensional porous carbon materials with complementary advantages and disadvantages is an important approach to addressing the structural and performance deficiencies of single carbon materials, while also significantly improving the electrochemical performance of super-capacitors. In this study, 1D hollow tubular/2D nanosheet hybrid dimensional porous carbon was synthesized through one-step carbonization using 1D fibrous brucite and 2D layered magnesium carbonate hydroxide as templates. By adjusting the feed ratio of 1D fibrous and 2D layered templates, the morphology, pore structure and specific surface area (SSA) of the prepared 1D hollow tubular/2D nanosheet hybrid dimensional porous carbon were controlled. The prepared hybrid dimensional porous carbons were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption. And their electrochemical performance was also studied by cyclic voltammograms (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the use of templates with different dimensions significantly influences the morphology, pore structure, SSA and electrochemical performance of the synthesized hybrid dimensional porous carbon. The hybrid dimensional porous carbon (3F) exhibits a high specific capacitance and excellent cycling stability. 3F demonstrates the specific capacitance of 245.3 F g-1 at 1 A g-1. Furthermore, the capacity retention rate remains as high as 93.4% after 8000 cycles at 10 A g-1. This work reveals that hybrid dimensional porous carbon composed of 1D hollow carbon tubes and 2D carbon nanosheets has great potential for use in supercapacitor electrode materials.

Enhancing properties of jute/starch bio-composite material through incorporation of magnesium carbonate hydroxide pentahydrate: A sustainable approach

This research aims to develop an environment-friendly composite material that possesses enhanced fire retardant (FR), thermal, as well as mechanical characteristics. The aim has been accomplished with the development of a jute/thermoplastic starch (TPS) based bio-composite. The fire retardancy and thermal stability of the jute/TPS composite were enhanced by the incorporation of magnesium carbonate hydroxide pentahydrate (MCHPH). Upon exposure to heat or fire, the MCHPH particles decompose in a two-stage process to yield water vapors and a char layer of MgO and CO2, which restrict access to oxygen and result in flame suppression. Moreover, the main contribution of the article is the improvement of mechanical properties simultaneously with the enhancement in the fire retardant and thermal properties, which have rarely been reported in the literature. The enhancement of mechanical properties is supported by the compatibility of MCHPH particles with jute/TPS. All the composites were developed with a constant 40 % jute fiber content, while the MCHPH concentration varied from 0 % to 9 % by weight. The tensile strength of TPS was enhanced by 595 % with the reinforcement of jute fiber and MCHPH nano-filler. Compatibility between TPS, jute, and MCHPH was discovered through Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was used to study the fractured surfaces of the composites. Thermo-gravimetric analysis (TGA) revealed a decrease in the weight loss of the MCHPH-filled jute/TPS composites at high temperatures. The vertical burning test also revealed that the composites met the requirements for a V-0 rating. The heat release rate of the composites was reduced by 36 % after the addition of MCHPH, as measured by cone calorimetry test. The biodegradability test confirmed the eco-friendly nature of the composites by demonstrating significant weight loss in soil over a 4-weeks period. Thus, the present study provided the basis for the development of a novel green composite with commendable gains in flame resistance, thermal stability, and mechanical robustness.

A Magnesium Carbonate Hydroxide Nanofiber/Poly(Vinylidene Fluoride) Composite Membrane for High-Rate and High-Safety Lithium-Ion Batteries.

Simultaneously high-rate and high-safety lithium-ion batteries (LIBs) have long been the research focus in both academia and industry. In this study, a multifunctional composite membrane fabricated by incorporating poly(vinylidene fluoride) (PVDF) with magnesium carbonate hydroxide (MCH) nanofibers was reported for the first time. Compared to commercial polypropylene (PP) membranes and neat PVDF membranes, the composite membrane exhibits various excellent properties, including higher porosity (85.9%) and electrolyte wettability (539.8%), better ionic conductivity (1.4 mS·cm-1), and lower interfacial resistance (93.3 Ω). It can remain dimensionally stable up to 180 °C, preventing LIBs from fast internal short-circuiting at the beginning of a thermal runaway situation. When a coin cell assembled with this composite membrane was tested at a high temperature (100 °C), it showed superior charge-discharge performance across 100 cycles. Furthermore, this composite membrane demonstrated greatly improved flame retardancy compared with PP and PVDF membranes. We anticipate that this multifunctional membrane will be a promising separator candidate for next-generation LIBs and other energy storage devices, in order to meet rate and safety requirements.

Enhancing the microstructure and surface texture of recycled concrete fine aggregate via magnesium-modified carbonation

Investigations on the carbonation of recycled concrete aggregates have been extensively carried out. In this work, recycled concrete fine aggregates (RCFs) were firstly treated with magnesium nitrate solutions of various concentrations and then carbonated. Extensive techniques were employed to characterize the changes of physical properties, pore structures, surface morphologies and phase assemblages of the RCFs after carbonation. Besides, the influences of carbonated RCFs on the hydration, compressive strength and phase assemblages of new cement systems were also evaluated. The results suggested that the magnesium-modified carbonation was more effective than pure carbonation in enhancing the microstructures of RCFs considering the reduction of total pore volume and water absorption. The refinement of microstructure was attributed to the formation of magnesium-calcite, hydromagnesite, etc. as a result of four sequential steps: adsorption of Mg2+ into RCF matrices, precipitation of magnesium hydroxide, enhanced dissolution of Ca2+ and the carbonation of magnesium hydroxide and calcium hydroxide mixes. In addition, the magnesium-modified carbonation was also found to significantly change the morphologies of carbonation products by generating spear-like magnesium-calcite, rosette-like hydromagnesite, plate-like hydrotalcite/mononitrate and spheroidal vaterite. The certain morphological changes of reaction products could promote the formation of an intersected 3D surface texture for RCFs. This particular surface texture could establish a well-connected interface with enhanced interlocking effects when the RCFs were used in new mortars, contributing to the bonding strength and compressive strength enhancement, and the best enhancement was achieved at low Mg2+ dosages (e.g., 0.05 M and 0.1 M).

Inerting mechanism of magnesium carbonate hydroxide pentahydrate for coal dust deflagration under coal gasification

To reduce the risk of coal dust deflagration caused by the leakage in the coal gasification process, a semi-closed vertical combustion tube was built with a high speed camera and micro-thermocouples. And the inerting effect of magnesium carbonate hydroxide pentahydrate (MCHP) with different particle sizes was investigated on the coal dust deflagration. The results showed that the initial flame became very faint and the brightness of the flame was greatly weakened after the addition of MCHP powder. And as the inerting ratio increased, both of the flame velocity and temperature decreased. When the particle size of MCHP powder decreased, the flame propagation time extended from 132 to 196, 223, and 228 ms respectively. And the residue analysis revealed that the decomposition of MCHP not only absorbed the highly reactive radicals of combustion, but also formed inert gases and heat-resistant protective film, which greatly reduced the deflagration intensity of coal dust.

Laser protective layers with incorporated mixtures of endothermic reactive materials for personal protective equipment

The lack of certified personal protective equipment (PPE) and the high number of quite ambitious requirements to laser protection clothes (protective, flexible, light-weight, processible, sewable, wearable, …) give rise to the development of a new kind of layered and functionalized textiles: Existing protective textiles acting as a substrate are coated with an additional layer consisting of compounds which can react in an energy-consuming, i.e. endothermic, manner. We report on recent progress on textile substrates which are equipped with endothermic mixtures of Fe2O3/C, SiO2/C, or Al2O3/Fe as well as compounds containing crystal water that can also be thermally decomposed, such as magnesium carbonate hydroxide hydrate. The resulting temperatures as well as the resistance to laser irradiation at 1064 nm after a duration of 30 s are used to judge the suitability for future personal protective equipment. A combination of an already available polyester textile substrate with the new magnesium carbonate hydroxide hydrate layer and a highly absorbing aluminum foil, treated by a Plasma Chemical Oxidation (PCO) method, shows promising results for application in laser protection textiles.

Preparation of hydrotalcite crystals using impinging jet mixers

The active pharmaceutical ingredient hydrotalcite (aluminium magnesium carbonate hydroxide hydrate) is an antacid marketed either as suspensions or tablets. It is necessary to have stringent control on multiple crystal properties not only due to the demand on high quality of the medicine but also as a result of the need to improving the efficiency of down-stream processing e.g. of filtration of crystals. This work investigated impinging jet mixers integrated with a stirred tank for the preparation of hydrotalcite crystals, using aluminum sulfate, sodium carbonate and porous magnesium hydroxide as the raw materials. The new process design has shown superior performance to the commonly used stirred tanks. The hydrotalcite crystals were of narrow particle size distribution, large size and high bulk density, high purity, and uniform morphology. An attempt was also made at trying to develop mechanistic understanding of the reactive crystallization processes taking place inside the integrated impinging jet mixers - stirred tank equipment. Firstly the impinging jet mixers enabled generation of ultrafine aluminum hydroxide particles during the reactive precipitation between sodium carbonate and aluminum sulfate aqueous solutions. Then, the ultrafine aluminum hydroxide accumulated in the shallow layer of the porous magnesium hydroxide particles and gradually filled the porous particles under the stirring effect of the tank reactor. Meanwhile, the magnesium hydroxide gradually reacted with aluminum hydroxide to generate hydrotalcite from the surface towards the inside of the particles, and finally produced the high quality hydrotalcite crystals.

Hydrothermal carbon dioxide fixation in magnesium hydroxide and serpentine: Effects of temperature and pH

This study investigated hydrothermal fixation of CO2 in serpentine or magnesium hydroxide as one of the compounds containing Mg at an initial CO2 pressure of 7.1 MPa. The carbonation of magnesium hydroxide gave primarily magnesite and the yield increased with increasing initial pH and increasing temperature, reaching 97.9 % at 473 K. Carbonation of serpentine also gave magnesite, and the yield initially increased and then slightly decreased with increasing temperature. Both low and high initial pH enhanced serpentine carbonation at 573 K and the yield of magnesite reached 12.7 % at an initial pH of 1.0. Estimation of chemical species indicated that both the dissolution of serpentine via the action of H+ and the formation of magnesite from MgHCO3+ and Mg2+ via the release of H+ were important reactions. Hydrothermal serpentine carbonation is a promising CO2 fixation method for naturally abundant mineral rocks without expensive additives.

The distribution of climbing chalk on climbed boulders and its impact on rock-dwelling fern and moss species.

Rock climbing is popular, and the number of climbers rises worldwide. Numerous studies on the impact of climbing on rock‐dwelling plants have reported negative effects, which were mainly attributed to mechanical disturbances such as trampling and removal of soil and vegetation. However, climbers also use climbing chalk (magnesium carbonate hydroxide) whose potential chemical effects on rock‐dwelling species have not been assessed so far. Climbing chalk is expected to alter the pH and nutrient conditions on rocks, which may affect rock‐dwelling organisms. We elucidated two fundamental aspects of climbing chalk. (a) Its distribution along nonoverhanging climbing routes was measured on regularly spaced raster points on gneiss boulders used for bouldering (ropeless climbing at low height). These measurements revealed elevated climbing chalk levels even on 65% of sampling points without any visual traces of climbing chalk. (b) The impact of climbing chalk on rock‐dwelling plants was assessed with four fern and four moss species in an experimental setup in a climate chamber. The experiment showed significant negative, though varied effects of elevated climbing chalk concentrations on the germination and survival of both ferns and mosses. The study thus suggests that along climbing routes, elevated climbing chalk concentration can occur even were no chalk traces are visible and that climbing chalk can have negative impacts on rock‐dwelling organisms.

Mechanism of formation of engineered magnesite: A useful mineral to mitigate CO2 industrial emissions

Magnesium carbonate production at the industrial scale is a realistic option to reduce the industrial emissions of CO2. Ultrabasic rocks and/or alkaline mine waste provide magnesium sources and are widely available in the Earth’s crust. Here, we investigated the aqueous carbonation of magnesium hydroxide under moderate temperature (25–90 °C) and pressure (initial pressure of CO2 = 50 bar) using NaOH as the CO2 sequestering agent. From time-resolved Raman measurements, we demonstrate that the aqueous carbonation of magnesium hydroxide can be an effective engineered method to trap CO2 into a solid material and produce large amounts of magnesite MgCO3 (6 kg/m3h), or hydromagnesite Mg5(CO3)4(OH)2.4H2O (120 kg/m3h) at 90 °C or nesquehonite MgCO3.3H2O (40 kg/m3h) at 25 °C. Higher production rates were measured for nesquehonite (at 25 °C) and hydromagnesite (at 60 and 90 °C). However, only the magnesite produced at 90 °C ensures a permanent CO2 storage because this mineral is the most stable Mg carbonate under Earth surface conditions, and it could be co-used as construction material in roadbeds, bricks with fire-retarding property and granular fill. The use of specific organic additives can reduce the reaction temperature to precipitate magnesite. For example, ferric EDTA (ethylenediaminetetraacetic acid) reduces the temperature from 90 to 60 °C. However, more time is required to complete magnesite precipitation reaction at this lower temperature (15 h at 90 °C and 7 days at 60 °C). These results suggests that functionalized organic groups can reduce the energetic barriers during magnesite nucleation.

High-Temperature Evolution of Point Defect Equilibria in Hydrous Forsterite Synthesized at 1100 °C and up to 4 GPa

Water distribution in the deep Earth represents one of the most important topics in the field of geodynamics due to its large impact on the physical and chemical properties of the Earth’s mantle, such as electrical conductivity, seismic anisotropy, diffusion, and rheology. In this study, we synthesized hydrous forsterite at 1100 °C and up to 4 GPa with either a piston-cylinder or multianvil apparatus. As a starting material, we used synthetic forsterite, unbuffered by SiO2, obtained by thermo-mechanical activation of talc and magnesium carbonate hydroxide. Hydration was carried out using liquid H2O as hydrogen source. Samples were polycrystalline in an effort to distribute H2O throughout the sample both rapidly and homogeneously. Using the Paterson calibration, we observed total water content concentrations ranging between 100 and 500 ppm wt H2O. Multiple absorption bands are found in the frequency range between 3400 and 3650 cm−1, identifying at least seven peaks in all samples. Vibrational bands were centered at 3476, 3535, 3550, 3566, 3578, 3605, and 3612 cm−1, in good agreement with experimental studies conducted on both hydrous forsterite and single crystals of olivine. The stronger OH stretching peaks can be attributed to vibrational modes associated with the hydrogarnet defect 4 H Si x in which four protons occupy a vacant tetrahedral site. None of the OH bands observed are found at frequencies associated with hydrogen occupying vacant octahedral sites. High-temperature FTIR spectroscopy was used to evaluate the evolution of IR spectra as a function of temperature, up to 500 °C. The complete reversibility of peak absorption vs. temperature in the OH stretching region confirms that no water loss occurred during heating. We observe an overall a decrease in total absorption with increasing temperature, and a prominent decrease in the relative intensities of the higher frequency bands (>3600 cm−1) with respect to lower frequency bands. We have assigned a series of equilibrium expressions based on the variation of relative peak areas with temperature and find that enthalpies of these processes range between 0.047–0.068 eV (4.5–6.5 kJ/mol), very low in comparison to activation energies observed for electrical conduction in hydrous olivine. Major changes in the vibrational spectrum are expected to be related to configurational changes of the same fully protonated hydrogarnet defect species. However, the complexity of the FTIR spectra may also be related to partially protonated defects, such as the associate defect 3 H Si ′ + H i • generated by a dissociation reaction of the hydrogarnet species.

Waffle production: influence of batter ingredients on sticking of waffles at baking plates-Part II: effect of fat, leavening agent, and water.

Fresh egg waffles are continuously baked in tunnel baking ovens in industrial scale. Waffles that partly or fully stick to the baking plates cause significant product loss and increased costs. The aim of this study was, therefore, to investigate the effect of different recipe ingredients on the sticking behavior of waffles. In this second part, ingredients investigated were different leavening agents (sodium acid pyrophosphate, ammonium bicarbonate, magnesium hydroxide carbonate, or monocalcium phosphate), different fat sources (rapeseed oil, cocos fat, butter, or margarine), and different water sources (tap water 12°dH and distilled water). Within the different types of fats, solid fats with high amount of short‐chain fatty acids (cocos fat or butter) decreased the number of sticking waffles compared to liquid oils (rapeseed oil). Regarding leavening agents, magnesium hydroxide carbonate and ammonium bicarbonate were superior to sodium acid pyrophosphate or monocalcium phosphate. Between the two water sources, effects were small.

Efficient removal of fluoride by hierarchical MgO microspheres: Performance and mechanism study

Hierarchical MgO microspheres assembled by numerous porous nanoplates were successfully obtained by annealing the precursors of magnesium carbonate hydroxide hydrate synthesized through a facile and cost-effective hydrothermal process at low temperature. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller measurements. The fluoride removal performance of the hierarchical MgO microspheres was investigated. The adsorption isotherm could be well fitted in Freundlich model, and the adsorption capacity was over 115.5mg/g at pH 7. The absorbent also showed high fluoride removal ability in a wide pH range of 2–10, which is favorable for practical application. The effect of co-existing anions on fluoride removal was also investigated. The result indicated that the fluoride adsorption capacity was influenced when carbonate, bicarbonate and phosphate existed above the concentration of 50mg/g. In addition, the adsorption mechanism was investigated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. A novel hydroxyl and carbonate co-exchange mechanism has been proposed for the first time. It can be found that fluoride ions could replace the surface carbonates which formed by the reaction of MgO and the adsorbed CO2 molecules, and then anchored on the MgO surface.

Crack-healing in spinel (MgAl2O4) ceramic

This paper reports the crack-healing behavior in spinel ceramic. Spinel nanopowder was synthesized via mechanical activation with subsequent annealing of magnesium carbonate and aluminum hydroxide. The produced nanopowder was uniaxially pressed and then sintered at 1200°C for 1h. Initial cracks were produced on the surface of the sintered bodies by Vickers indenter to investigate the healing behavior of spinel after various heat treatment regimes. It was found that cracks can be healed completely after annealing the specimens at 1600°C for 100h. Those specimens sintered at lower temperatures and/or sintered for less times showed partial healing. The results demonstrated that sintering process and abnormal grain growth are responsible for crack-healing in spinel. Also the healing efficiency was expressed as the strength recovery of the pre-cracked samples after healing procedures and was evaluated by diametral tensile strength (DTS) test or indirect tensile test (ITT). It was found that the strength recovery of those samples heat treated at 1600°C for 100h was about 91%, which suggests high healing efficiency.

Using electrochemical process to mineralize CO2 and separate Ca2+/Mg2+ ions from hard water to produce high value-added carbonates

CO2 mineralization is a promising utilization option for reducing CO2 emissions. Hard water (e.g. seawater, salt water and brine) rich in Ca2+ and Mg2+ ions, has potential for fixation of CO2. But to date there is no effective way to use these ions for CO2 mineralization. In this paper, a novel method based on membrane electrolysis was proposed and used for carbonation and separation of calcium and magnesium ions from hard water in low voltage. Compared with traditional electrolysis, membrane electrolysis can reduce the voltage by about 1.3 V, which reducing the energy consumption for CO2 mineralization dramatically. This method was proved effective to remove the Ca2+/Mg2+ ions from hard water. And CO2 was finally transformed into marketable pure magnesium carbonate and precipitated calcium carbonate. According to this study, 1000 m3 of concentrated seawater could mineralize 4.65 tons of CO2. In addition, 9.97 tons of magnesium carbonate hydroxide and 2.02 tons of precipitated calcium carbonate could be produced with only a total electric power consumption of 5676 kWh. Therefore, this method affords a new route for CO2 mineralization by transforming hard water into high value-added industrial products with low energy consumption.

Template-induced synthesis and superior antibacterial activity of hierarchical Ag/TiO2composites

Hierarchical Ag/TiO2composites were successfully synthesizedviahydrated magnesium carbonate hydroxide template-induced route, which exhibit superior and long-term antimicrobial activity.

Experimental etch-and-rinse adhesives doped with bioactive calcium silicate-based micro-fillers to generate therapeutic resin–dentin interfaces

ObjectivesThis study aimed at evaluating the therapeutic bioactive effects on the bond strength of three experimental bonding agents containing modified Portland cement-based micro-fillers applied to acid-etched dentin and submitted to aging in simulated body fluid solution (SBS). Confocal laser (CLSM) and scanning electron microscopy (SEM) were also performed. MethodsA type-I ordinary Portland cement was tailored using different compounds such as sodium–calcium–aluminum–magnesium silicate hydroxide (HOPC), aluminum–magnesium–carbonate hydroxide hydrates (HCPMM) and titanium oxide (HPCTO) to create three bioactive micro-fillers. A resin blend mainly constituted by Bis-GMA, PMDM and HEMA was used as control (RES-Ctr) or mixed with each micro-filler to create three experimental bonding agents: (i) Res-HOPC, (ii) Res-HCPMM and (iii) Res-HPCTO. The bonding agents were applied onto 37% H3PO4-etched dentin and light-cured for 30s. After build-ups, they were prepared for micro-tensile bond strength (μTBS) and tested after 24h or 6 months of SBS storage. SEM analysis was performed after de-bonding, while CLSM was used to evaluate the ultra-morphology/nanoleakage and the mineral deposition at the resin–dentin interface. ResultsHigh μTBS values were achieved in all groups after 24h. Only Res-HOPC and Res-HCPMM showed stable μTBS after SBS storage (6 months). All the resin–dentin interfaces created using the bonding agents containing the bioactive micro-fillers tested in this study showed an evident reduction of nanoleakage and mineral deposition after SBS storage. ConclusionResin bonding systems containing specifically tailored Portland cement micro-fillers may promote a therapeutic mineral deposition within the hybrid layer and increase the durability of the resin–dentin bond.

Influence of Mg surface layer for induction period of Grignard reagent formation

Factors that affect the induction period of Grignard reagent formation, which involves heterogeneous reaction between magnesium metal (Mg) and an alkyl halide in ether solvent, has been clarified to achieve safer and more efficient operation in chemical processes. The influence of the Mg surface, especially the effects of carbonate, hydroxide, and oxide layers on the induction period were investigated by measuring the exothermic behavior of Grignard reagent formation by a differential reaction calorimeter. Mg powder was kept in water bubbled with CO2 or N2 gas to form a coating on the Mg surface. The calorimetry results for the reaction indicated that both treatments increased the induction period. Thermogravimetric analysis-mass spectrometry was conducted to identify the chemical species and quantify the amount of surface material on the Mg particles. It was found that basic magnesium carbonate and magnesium hydroxide were formed on Mg exposed to CO2 and N2, respectively. Subsequent heating the carbonate- or hydroxide-coated Mg at 500 °C caused a MgO layer to form on the surface, which was found to dramatically reduce the induction period.

A facile template free solution approach for the synthesis of dypingite nanowires and subsequent decomposition to nanoporous MgO nanowires with excellent arsenate adsorption properties

In this paper, one-dimensional (1-D) dypingite (hydrated magnesium carbonate hydroxide, Mg5(CO3)4(OH)2·5H2O) nanowires with several hundreds micrometers in length were synthesized at 100 °C by a simple solution method without using any template or catalyst for the first time. A plausible diffusion growth model for the growth of the dypingite nanowires was proposed. The influences of the magnesium ion concentrations and the magnesium sources on the structures of the products were also studied. The as-synthesized nanowires were an excellent precursor for the fabrication of 1-D nanoporous magnesium oxide (MgO) nanowires via a simple thermal transformation process. Room temperature photoluminescence studies suggest that the nanoporous MgO nanowires show a strong ultraviolet emission and a weak blue emission. The adsorption properties of the porous MgO nanowires were investigated for As(V) removal. A high As(V) adsorption capacity of 384.6 mg g−1 was realized, which was resulted from the reaction between the As(V) species and MgO in aqueous solution.