Latest Research from a Highly Cited Scholar: XPS Insights into the Electronic Structure Regulation Mechanisms of Minerals｜OAJRC Material Science

"Why do azurite and malachite, both copper-bearing minerals, exhibit such striking differences in color, stability, and physicochemical properties?" "Has our understanding of minerals advanced beyond their macroscopic appearance to the fundamental level of electronic structure?" These questions are not only central to the advancement of mineralogical theory but also have profound implications for resource utilization, materials design, and environmental geochemistry.

In the paper "Chemical Bonding and Electronic Structures of Azurite and Malachite by X-Ray Photoelectron Spectroscopy," published in OAJRC Material Science, J. Theo Kloprogge from the Department of Chemistry, College of Arts and Sciences, The University of the Philippines Visayas, Philippines, employs X-ray Photoelectron Spectroscopy (XPS) to systematically investigate the chemical bonding characteristics and electronic structures of azurite and malachite. The study provides valuable insights into the formation mechanisms and physicochemical properties of copper carbonate minerals from an electronic perspective.

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From Color to Electrons: Unveiling the Microscopic World of Copper Minerals

The deep blue of azurite and the vibrant green of malachite have fascinated people for centuries. Yet, beneath these remarkable natural colors lies the true determinant of mineral properties—not their appearance, but the nature of chemical bonds and the distribution of electrons among atoms. Serving as a powerful tool for probing the electronic world, X-ray Photoelectron Spectroscopy (XPS) enables researchers to identify elemental chemical states, electronic environments, and bonding characteristics by analyzing variations in binding energies. This approach not only reveals the evolution of electronic structures during mineral formation but also explains why these two classic copper minerals exhibit distinctly different physicochemical behaviors. It opens a new window into understanding minerals at the electronic level.

Electronic Structure Determines Performance: Why Fundamental Research Matters

In modern mineralogical research, scientists increasingly recognize that the value of a mineral extends beyond its chemical composition to its electronic structure. Electronic structures govern a mineral's stability, chemical reactivity, electrical conductivity, catalytic performance, and weathering behavior. From mineral resource extraction and processing to the development of advanced energy materials, a precise understanding of electronic structures has become an essential foundation of contemporary materials science. With the rapid advancement of high-resolution characterization techniques, researchers are revisiting traditional minerals from atomic and electronic perspectives. This shift is transforming mineralogy from descriptive observations to mechanistic understanding while enabling the rational design of advanced materials. True scientific innovation often begins with answering the most fundamental questions.

XPS: A Critical Bridge Between Fundamental Science and Advanced Materials

As one of the most powerful characterization techniques in modern materials science, X-ray Photoelectron Spectroscopy (XPS) has found extensive applications in mineralogy, catalysis, energy materials, semiconductors, and biomedical materials. By accurately determining elemental chemical states and binding energies, XPS not only reveals compositional changes on material surfaces but also elucidates chemical bonding mechanisms, providing reliable guidance for optimizing material performance. From lithium-ion battery electrodes and catalytic active sites to environmental mineral interfaces, numerous scientific breakthroughs have relied on XPS for atomic-level insights. This study highlights the indispensable role of advanced characterization technologies in fundamental mineral research and demonstrates that a comprehensive understanding of electronic structures is essential for the precise regulation and design of material properties.

From Natural Minerals to Future Materials: Unlocking New Possibilities Through Electronic Structure Research

Azurite and malachite are not only important natural copper ores but also serve as ideal model systems for studying copper-based functional materials. As research in renewable energy, energy storage, green catalysis, and environmental remediation continues to expand, the demand for a deeper understanding of material electronic structures is growing rapidly. In the future, theoretical knowledge derived from the electronic structures of natural minerals may contribute to the design of high-performance catalysts, advanced ceramic materials, efficient mineral resource utilization, and the regulation of environmental interfacial reactions. Every mineral records the history of Earth's evolution, while every electron holds the key to understanding material performance. As fundamental research continues to advance, humanity is gradually moving from simply observing minerals to truly understanding them at the electronic level. "The future of materials is determined not merely by what they are made of, but by how their electrons connect and interact." By uncovering the essence of minerals through their electronic structures, materials science gains a stronger theoretical foundation while opening new opportunities for sustainable materials, advanced manufacturing, and the efficient utilization of natural resources.

The study was published in OAJRC Material Science

https://www.hillpublisher.com/ArticleDetails/6691

How to cite this paper

J. Theo Kloprogge. (2026) Chemical Bonding and Electronic Structures of Azurite and Malachite by X-Ray Photoelectron Spectroscopy. OAJRC Material Science, 8(1), 37-53.

DOI: http://dx.doi.org/10.26855/oajrcms.2026.06.004

Scholar Introduction

Prof. J. Theo Kloprogge is an internationally recognized researcher in the fields of mineralogy, clay mineral science, geochemistry, and mineral spectroscopy. He currently serves as an Adjunct Professor at the University of the Philippines Visayas. Over the course of his academic career, he has made sustained contributions to the understanding of the structure, properties, characterization, and applications of minerals and earth materials, earning broad recognition within the international mineralogical and geochemical research communities.

His research interests encompass clay minerals, layered double hydroxides (LDHs), environmental mineralogy, geochemistry, mineral spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and the characterization of natural and synthetic earth materials. His work has significantly advanced the understanding of mineral structures, surface chemistry, reaction mechanisms, and the environmental behavior of mineral materials, with applications extending to environmental remediation, material science, catalysis, and geological processes.

Screenshot of J. Theo Kloprogge's Scopus Author Profile

The author has established broad international academic recognition, as reflected by the following scholarly metrics:

• Google Scholar: 23,354 citations, h-index of 80, and i10-index of 272.
• Scopus: 287 indexed publications, 16,987 citations, and an h-index of 66.

These consistently strong citation metrics demonstrate the author's sustained research impact, long-term scholarly contributions, and broad recognition within the international scientific community.

He has published extensively in leading international peer-reviewed journals and has collaborated with researchers from numerous countries on interdisciplinary studies in mineralogy, geochemistry, environmental science, and materials research. His publications have become important references in the fields of clay mineralogy, mineral spectroscopy, and earth-material characterization. Through his continued research and scholarly collaborations, he has made significant contributions to advancing mineralogical sciences and promoting the development of earth and environmental materials research worldwide.