Submit to Crystals Review for Crystals Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation

Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A Special Issue of Crystals (ISSN 2073-4352).

Deadline for manuscript submissions: closed (15 August 2026) | Viewed by 6760

Share This Special Issue

Editors

Prof. Dr. Limei Wu

E-Mail Website
Guest Editor

School of Materials Science and Engineering, Shenyang Jianzhu University, Shenyang 110168, China
Interests: low dimensional materials; condensed matter physics; material science; atomic and molecular nanostructures; spintronics and magnetronics

Dr. Xin Liu

E-Mail Website
Guest Editor

School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China
Interests: mineral materials; computational materials science; environmental materials; catalytic materials

Dr. Qingfeng Guo

E-Mail Website
Guest Editor

School of Gemology, China University of Geosciences, Beijing 100083, China
Interests: luminescence materials; crystal structure; gemology
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Crystals, characterized by their highly ordered atomic structures, serve as foundational units for deciphering the properties and applications of materials. In mineralogy, crystallographic analysis remains indispensable for mineral identification and classification, as well as the elucidation of formation mechanisms, stability fields, and structure–property relationships. Beyond natural mineral systems, rationally designed crystalline materials, including zeolites, perovskites, metal–organic frameworks (MOFs), and their derivatives, are redefining frontiers in functional materials science, enabling breakthroughs in catalysis, renewable energy technologies, and environmental applications such as carbon capture and pollutant sequestration. Particularly, integrating artificial intelligence with crystal structure prediction and design can accelerate the R&D cycle, reduce trial-and-error costs, and significantly expedite the development of novel crystal materials. Equally transformative is the role of crystalline phases in sustainable waste management. Industrial byproducts (e.g., metallurgical slags, fly ash, and construction residues) are increasingly recognized as secondary resource reservoirs. By transforming waste into valuable crystalline materials, we can reduce environmental impacts and promote circular economy principles. This Special Issue explores the synergistic convergence of crystallography, mineral materials science, and solid waste valorization. We welcome contributions that highlight the potential of crystals to drive technological and environmental progress, leading to a paradigm shift in materials innovation and waste-to-resource transitions

Prof. Dr. Limei Wu
Dr. Xin Liu
Dr. Qingfeng Guo
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2100 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

mineral crystallography
mineral materials
solid waste valorization
AI-driven material design

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Published Papers (8 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

24 pages, 37696 KB

Open AccessArticle

Valorization of Red Mud, Steel Slag, and Desulfurization Slag as Industrial Solid-Waste-Derived Catalysts for Ciprofloxacin Degradation via H₂O₂ and Peroxymonosulfate Activation

by Yan Lin, Jingyan Li, Jiayu Yang, Rui Xu, Dunqiu Wang, Kun Dong, Ruize Sun and Mingrong Wei

Crystals 2026, 16(7), 450; https://doi.org/10.3390/cryst16070450 - 11 Jul 2026

Cited by 1 | Viewed by 430

Abstract

This study used red mud (RM), steel slag (SS), and desulfurization slag (DS) as raw materials to construct three catalytic oxidation systems, namely RM-DCDA/H₂O₂, SS-DS/H₂O₂, and SS-DS/peroxymonosulfate (PMS), to promote the utilization of industrial solid waste and enhance the treatment of recalcitrant antibiotic wastewater. The ciprofloxacin (CIP) degradation performances, influencing factors, and preliminary reaction mechanisms of these systems were investigated. RM formed an Fe₃N/C composite structure after acidification and dicyandiamide-assisted calcination. The Fe₃N active phase, coexistence of Fe²⁺/Fe³⁺, and N-doped C structure facilitated H₂O₂ activation and electron transfer. The SS-DS catalyst exhibited a rough and porous structure and contained Fe, Ca, and S species, which could provide reactive sites for H₂O₂ and PMS activation, following acid modification and urea-assisted calcination. Under the necessary reaction conditions, the CIP degradation efficiencies of the RM-DCDA/H₂O₂, SS-DS/H₂O₂, and SS-DS/PMS systems reached 94.60%, 92.58%, and 95.17%, respectively. These results indicate that RM- and SS-derived materials can be used for CIP oxidative degradation; however, the values should not be interpreted as a strict comparison of the intrinsic catalytic activity because the operating conditions differed among the systems. Parametric experiments showed that the catalyst dosage, oxidant concentration, and initial pH influenced the degradation efficiency. The H₂O₂-based systems were more suitable under acidic conditions, whereas the SS-DS/PMS system showed wider pH adaptability. Coexisting anion and humic acid experiments indicated that the systems were tolerant to natural organic matter, whereas HCO₃⁻ and HPO₄²⁻ inhibited degradation. CIP was further oxidized in total organic C and recycling experiments; however, it was difficult to completely mineralize it within a short reaction time, and the catalyst retained relatively high activity after repeated use. Radical quenching experiments suggested that ·OH and ·O₂⁻ participated in the degradation reactions in the RM-DCDA/H₂O₂ and SS-DS/H₂O₂ systems. In the SS-DS/PMS system, comparative quenching experiments revealed that non-radical singlet oxygen (¹O₂) was the dominant reactive species, while SO₄⁻· and ·OH contributed only marginally. In conclusion, RM and SS-DS can be used as low-cost raw materials to prepare industrial solid-waste-derived catalysts for the oxidative degradation of CIP, thereby providing a reference for industrial solid waste valorization and antibiotic wastewater treatment. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

21 pages, 11691 KB

Open AccessArticle

Microstructural Evaluation of Plasma-Vitrified Wind Turbine Blade Slag and Its Alternative Application in Geopolymer

by Vilma Snapkauskienė, Regina Kalpokaitė-Dičkuvienė, Arūnas Baltušnikas and Viktorija Grigaitienė

Crystals 2026, 16(5), 334; https://doi.org/10.3390/cryst16050334 - 15 May 2026

Viewed by 533

Abstract

With the rapid expansion of wind energy infrastructure, there is an increasing accumulation of wind turbine blade waste (WTBW), which is mainly composed of glass fiber-reinforced thermosetting composites. Due to the irreversible nature of polymer crosslinking, conventional recycling methods remain limited. In this study, plasma vitrification was employed to convert WTBW into a reactive calcium-aluminum-silicate slag suitable for use in geopolymer materials. Plasma treatment at a temperature of approximately 2750 K resulted in the formation of predominantly amorphous vitrified slag (VS). Structural characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) revealed the spatial heterogeneity of the VS. This heterogeneity was influenced by thermal gradients and varied between samples collected from different slag discharge zones, both vertically and horizontally from the reactor. All VS samples contained between 30 and 89% amorphous phase and 10–55% anorthite, with the proportions varying by sampling location. Chemical stability tests showed the dissolution of calcium and aluminum in acidic media, resulting in a silica-enriched residual structure in which the Ca and Al content decreased to less than 0.5 at.% after 100 days. In contrast, exposure to alkaline media caused only minimal surface reorganization—the addition of 5 wt.% VS to acid-based geopolymers made with two metakaolin precursors resulted in a 35% decrease in the mechanical strength of pure metakaolin-based systems. In contrast, when metakaolin containing illite impurities was used, strength values were similar to those of the reference geopolymer. The results quantitatively demonstrate that plasma-derived slag exhibits composition-dependent reactivity, directly linked to its amorphous content and dissolution behavior. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

20 pages, 4362 KB

Open AccessArticle

Synthesis, Characterization and Application of Hybrid ZnO Nanoparticles in the Adsorption of Heavy Metals from Aqueous Solutions

by Ghadah M. Al-Senani, Salhah D. Al-Qahtani, Lamia M. Alotaibi, Wajd H. Alsahli, Lujain K. Alanazi, Abeer M. Alshalwi, Noura A. Alhamidi and Ghaday T. Alsubaie

Crystals 2026, 16(4), 231; https://doi.org/10.3390/cryst16040231 - 31 Mar 2026

Viewed by 956

Abstract

Hybrid material-derived adsorbents have demonstrated exceptional efficacy in a variety of fields, including environmental cleanup and manufacturing operations. In this study, zinc oxide nanoparticles modified with carbon (ZnO-C) as hybrid adsorbent materials were synthesized using both expired zinc chloride and corncob extract. Hybrid ZnO-C adsorbents were employed for the removal of heavy metals, Co(II), and Ni(II) ions, from wastewater via adsorption. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy dispersive spectroscopy (EDS) were among the methods used to fully characterize the structural and morphological properties. To maximize the adsorption process for every metal ion, kinetic and equilibrium studies were carried out. Results revealed that the ZnO-C material formed crystalline, spherical granules with nanoparticle sizes ranging from 25 nm, embedded within a carbon matrix. Additionally, these spherical zinc oxide particles tended to aggregate into clusters. FTIR analysis indicated that the surface of ZnO-C was rich in hydroxyl (OH) groups and zinc oxide, which play a crucial role in the adsorption mechanism. The capacity of ZnO/CC-NPs to adsorb cobalt and nickel ions from aqueous solutions was investigated, examining the influences of initial ion concentration, pH levels, contact duration, and temperature. The findings highlight the high efficiency of ZnO/CC-NPs as an adsorbent, promoting the reuse of waste materials and supporting environmental sustainability efforts. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

23 pages, 4564 KB

Open AccessArticle

Influence of Binary Precursors on Wood Biomass Ash-Based Alkali-Activated Materials: A Comparative Study

by Yiying Du, Jolanta Pranckevičienė and Ina Pundienė

Crystals 2026, 16(3), 204; https://doi.org/10.3390/cryst16030204 - 17 Mar 2026

Viewed by 1155

Abstract

The valorisation of significant quantities of wood biomass ash (WBA) in the production of building and construction materials is a sustainable approach to waste management. Due to their low chemical reactivity, the challenge for WBA-based alkali-activated materials (AAM) is improving their mechanical properties. To address this issue, WBA, containing wood biomass bottom ash and wood biomass fly ash, was used as the primary precursor. One aluminosilicate-rich material (coal fly ash (CFA), metakaolin (MK), or natural zeolite (NZ)) was added as a binary precursor at 10, 20, 30, and 40% of the total precursor mass (the mass of WBA plus the binary precursor) to compare its effectiveness. In the overall composition, the proportion of these aluminosilicate precursors was only 3.3–13.3%. Alkali activators consisted of 10% calcium hydroxide, 7 mol/L sodium hydroxide, and sodium silicate with the same solute mass as sodium hydroxide. Compressive strength and microstructural examinations (SEM-EDS, TG-DTA, XRD, XRF, and FTIR) were conducted on the produced AAM to analyse the mechanical performance and reaction mechanisms. A cradle-to-gate lifecycle assessment (LCA) was performed to evaluate the environmental impacts, including greenhouse gas emissions and energy consumption. The results show that NZ increased compressive strength by up to 57.62% when used at 6.6% in the composition. At the same time, MK and CFA increased strength by 33.05% and 47.15%, respectively. Binary precursors increased the greenhouse gas emissions and energy demands of AAM products, especially the MK, due to its energy-intensive calcination process. From a comprehensive view, NZ is the most efficient choice based on both mechanical and environmental insights. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

26 pages, 7253 KB

Open AccessArticle

Effects of Total Calcium and Iron(II) Concentrations on Heterogeneous Nucleation and Crystal Growth of Struvite

by Pengcheng Wei, Kaiyu Deng, Yang Huang, Jiayu Yang, Fujiang Hui, Dunqiu Wang and Kun Dong

Crystals 2026, 16(2), 80; https://doi.org/10.3390/cryst16020080 - 23 Jan 2026

Viewed by 852

Abstract

This study investigated the effects of calcium (Ca²⁺) and iron (II) Fe²⁺ concentrations (0–500 mg/L) on the heterogeneous nucleation and crystallization behavior of struvite (MgNH₄PO₄·6H₂O) through controlled batch precipitation experiments. Struvite formed under different Ca²⁺ and Fe²⁺ concentrations were systematically characterized using XRD, SEM, FTIR, and XPS, while real-time pH and redox potential (Eh) monitoring was employed to elucidate reaction dynamics and thermodynamic speciation and saturation indices were calculated, and classical nucleation theory (CNT) was applied to interpret nucleation behavior. The results show that Ca²⁺ primarily suppresses struvite formation through bulk-phase competition with Mg²⁺ for phosphate, diverting phosphate into Ca–P phases and progressively reducing struvite supersaturation, which leads to decreased crystallinity and distorted Crystal habit. In contrast, Fe²⁺ does not form detectable crystalline Fe-P phases but inhibits struvite crystallization mainly through surface-mediated processes. Surface analyses indicate that Fe-bearing species adsorb onto struvite surfaces and promote amorphous Fe-P deposition, increasing interfacial resistance to nucleation and growth. CNT analysis further reveals that Ca²⁺ inhibition is governed by reduced thermodynamic driving force, whereas Fe²⁺ inhibition is dominated by surface-related kinetic barriers. This study provides mechanistic insight into ion-specific interference during struvite crystallization and offers guidance for optimizing phosphorus recovery in ion-rich wastewater systems. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

14 pages, 3220 KB

Open AccessArticle

Effect of Stone Powder Content on the Properties and Microstructure of Nuclear Power-Manufactured Sand Concrete

by Xiangqin Du, Zhilong Liu, Rongfei Chen, Zhenhua Zhao, Xiaobo Hao, Xiaofan Peng and Hongmei Wu

Crystals 2026, 16(1), 66; https://doi.org/10.3390/cryst16010066 - 19 Jan 2026

Viewed by 781

Abstract

Stone powder is an inevitable by-product generated during the processing of manufactured sand and gravel. Waste stone powder has been proven to affect concrete properties and has been applied in the transportation and hydropower fields. This study aims to convert waste granite stone powder (GP) to nuclear power concrete by replacing manufactured sand, investigating its effect on the workability, compressive strength, splitting tensile strength, impermeability, and freezing resistance of nuclear power concrete. The mechanism was further elucidated through thermogravimetric (TG), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP) techniques. The results show that with the increase in GP content, the slump, compressive strength, and splitting tensile strength of concrete increase first and then decrease, and the seepage height under pressure water decreases first and then increases. The workability, strength, and impermeability of concrete are optimal when GP content is 11.0%. Reasonable GP content improves the compactness of concrete by filling pores and optimizing aggregate gradation, resulting in decreases in porosity, with the size being the most probable and average pore size. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

18 pages, 4965 KB

Open AccessArticle

Research on Activation of Solid Waste Through Microbial Desilification

by Yuming Bai, Xiao Li, Limei Wu and Haiyang Qiao

Crystals 2026, 16(1), 54; https://doi.org/10.3390/cryst16010054 - 12 Jan 2026

Viewed by 567

Abstract

To investigate the biosilicification capabilities of Bacillus mucilaginosus and Bacillus polymyxa, silicon concentrations in supernatants from quartz and calcium silicate cultures were monitored over a 12-day period using inductively coupled plasma optical emission spectrometry (ICP-OES). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to evaluate changes in the absorption intensity of Si–O–Si characteristic peaks, crystalline phase transformations in the reaction products, and the microstructural morphology of quartz and calcium silicate before and after microbial leaching. The results show that after leaching with B. mucilaginosus, the dissolved silicon concentration in the quartz supernatant reached a maximum of 73.868 mg/L on day 8. In contrast, following treatment with B. polymyxa, the silicon concentration in the calcium silicate supernatant peaked earlier, at 149.153 mg/L on day 4. After microbial leaching, both substrates exhibited marked changes in the intensity of the infrared absorption peaks at 1071 cm⁻¹ and 1083 cm⁻¹, suggesting the formation of Si–O–R type organosilicon complexes. Iron tailings (containing inert silica) and fly ash (containing active silica) were selected for experimental validation. Following treatment with B. mucilaginosus for desilication over an 8-day period, the activity index of iron tailings increased from 77.83% to 90.51%, while that of fly ash rose from 66.32% to 85.01%. ICP-OES analysis confirmed that under the action of B. mucilaginosus, the trends in silicon concentration and activity index in the supernatant of silica-containing solid wastes, such as iron tailings and fly ash, were consistent with those observed in quartz, thereby demonstrating effective biological desilication. These findings provide novel insights into the development of environmentally sound disposal methods for a wider range of solid waste types. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Figure 1

15 pages, 5335 KB

Open AccessArticle

Autoclave Expansion and Compressive Strength of MgO-Admixed RCC with Partial Fly Ash Replacement by Phosphorus Slag

by Rongfei Chen and Changli Chen

Crystals 2025, 15(12), 1048; https://doi.org/10.3390/cryst15121048 - 11 Dec 2025

Cited by 1 | Viewed by 593

Abstract

High-volume fly ash (FA) mitigates the expansion of magnesium oxide (MgO), and the uneven regional distributions of high-quality FA collectively limit the application of roller-compacted concrete admixed with MgO (M-RCC). This study evaluated the autoclave expansion and compressive strength of MgO-admixed cement paste and mortar, wherein phosphorus slag (PS) was used to partially or fully replace FA. The expansion mechanism within the MgO-FA-PS system was explored. Results show that the autoclave expansion of the mortar increased as the proportion of PS replacing FA rose. At a replacement ratio of 33% (i.e., 20% of the total mass of cementitious materials), the mortar maintained the same ultimate MgO dosage (8%) as the control specimen, yet exhibited a 12.7% increase in expansion and an 8.8% decrease in strength. The mechanism is that PS is less efficient than FA in reducing the pore solution alkalinity, thereby promoting the formation of more brucite. The growth pressure of brucite crystals expands the internal gaps in the matrix and coarsens the pore size, resulting in greater expansion and reduced compressive strength. The results of this study can provide theoretical and technical insights for the application of PS in M-RCC. Full article

(This article belongs to the Special Issue Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation)

► Show Figures

Journal Menu

Journal Browser

Synergizing Crystallography, Mineral Materials Science and Solid Waste Upcycling for Sustainable Materials Innovation

Share This Special Issue

Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (8 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI