The use of fossil fuels for energy generation is a well-known environmental issue. To overcome this problem, it is vital to discover a pollution-free energy source where hydrogen is used as a renewable energy resource. Due to its abundance on earth and zero carbon emission, it can substitute fossil fuels. Electrochemical water splitting is best method for producing molecular hydrogen as a sustainable energy source. Herein, a nanocomposite of transition metal-based spinel with rGO was synthesized by solvothermal method for OER activity. Various analytical approaches were employed to analyze the CoCr2O4/rGO composite that revealed its phase structure. The BET adsorption isotherm showed that its structure was mesoporous. Due to their unique mesoporous configuration, CoCr2O4/rGO composite shows enhanced electrical conductivity, improved thermal stability, and increased surface area. Furthermore, Electrochemical tests of composite in 1 M KOH revealed a lower overpotential 274 mV and Tafel 53 mV dec−1 for OER. The exceptional findings achieved by electrochemical activity imply that nanocomposite of CoCr2O4/rGO acts as excellent electrocatalyst for OER applications.
{"title":"Preparation of nano-composite of CoCr2O4 with rGO by solvothermal method for water splitting","authors":"Sidra Jabeen , Ashfaq Ahmad , Abhinav Kumar , Sarah A. Alsalhi , Jayanti Makasana , Suhas Ballal , R.S.K. Sharma , Piyus Kumar Pathak , Rahul Raj Chaudhary , Vijayalaxmi Mishra","doi":"10.1016/j.diamond.2025.112167","DOIUrl":"10.1016/j.diamond.2025.112167","url":null,"abstract":"<div><div>The use of fossil fuels for energy generation is a well-known environmental issue. To overcome this problem, it is vital to discover a pollution-free energy source where hydrogen is used as a renewable energy resource. Due to its abundance on earth and zero carbon emission, it can substitute fossil fuels. Electrochemical water splitting is best method for producing molecular hydrogen as a sustainable energy source. Herein, a nanocomposite of transition metal-based spinel with rGO was synthesized by solvothermal method for OER activity. Various analytical approaches were employed to analyze the CoCr<sub>2</sub>O<sub>4</sub>/rGO composite that revealed its phase structure. The BET adsorption isotherm showed that its structure was mesoporous. Due to their unique mesoporous configuration, CoCr<sub>2</sub>O<sub>4</sub>/rGO composite shows enhanced electrical conductivity, improved thermal stability, and increased surface area. Furthermore, Electrochemical tests of composite in 1 M KOH revealed a lower overpotential 274 mV and Tafel 53 mV dec<sup>−1</sup> for OER. The exceptional findings achieved by electrochemical activity imply that nanocomposite of CoCr<sub>2</sub>O<sub>4</sub>/rGO acts as excellent electrocatalyst for OER applications.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112167"},"PeriodicalIF":4.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amorphous carbon (a-C:I) thin films have been developed on glass substrates by a simplistic PE-CVD method. The films have been synthesized from CH3I solution with iodine added at a concentration of 0.5 mg/mL. XRD study elicits the amorphous nature of the films. SEM images reveal that the films are disk-like and rough. EDS data ensures that the thin films mainly composed of carbon and iodine. The FTIR spectra reveal the stretching vibration of CI bond. Transmittance of the films initially increases with time and then stabilized. The bandgap of the synthesized a-C:I thin films have been calculated to be in the range of ∼2.12 to 2.45 eV. The findings are promising for the applications of a-C:I films in optoelectronic devices.
{"title":"Synthesis of amorphous carbon (a-C) thin films from the iodomethane chemical route by PE-CVD method for optoelectronic devices","authors":"Shochin Chandra Das , Jaker Hossain , Md. Mahbubor Rahman , Mamunur Rashid Talukder","doi":"10.1016/j.diamond.2025.112173","DOIUrl":"10.1016/j.diamond.2025.112173","url":null,"abstract":"<div><div>Amorphous carbon (a-C:I) thin films have been developed on glass substrates by a simplistic PE-CVD method. The films have been synthesized from CH<sub>3</sub>I solution with iodine added at a concentration of 0.5 mg/mL. XRD study elicits the amorphous nature of the films. SEM images reveal that the films are disk-like and rough. EDS data ensures that the thin films mainly composed of carbon and iodine. The FTIR spectra reveal the stretching vibration of C<img>I bond. Transmittance of the films initially increases with time and then stabilized. The bandgap of the synthesized a-C:I thin films have been calculated to be in the range of ∼2.12 to 2.45 eV. The findings are promising for the applications of a-C:I films in optoelectronic devices.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112173"},"PeriodicalIF":4.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanocomposites that integrate electrostatic charge accumulation and faradic reaction mechanisms hold significant potential as high-performance supercapacitor electrodes for electrochemical energy storage. However, the development of low-cost carbon composites derived from renewable resources remains challenging. Herein, we demonstrate two different conducting polymers such as polyaniline (PA) and polypyrrole (PP) with incorporation of biomass-derived activated carbon from Strychnos Potatorum shells (SPAC) through in-situ polymerization. The SPAC was prepared through pre‑carbonization followed by a physical activation method. The structural defects of the as-synthesized polymer composites were characterized thoroughly by various physicochemical techniques including Fourier transform infrared (FT-IR), Raman, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and Field emission scanning electron microscopy (FE-SEM). Further, the PA and PP composite electrode materials were examined by electrochemical methods such as cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. Under the optimal conditions, the high specific capacitance was observed in PA@SPAC30 (214 F g−1) at 1.0 A g−1 compared to other composites such as PA@SPAC5 (35.2 F g−1), PA@SPAC10 (75.2 F g−1), PA@SPAC15 (101.4 F g−1), PA@SPAC50 (175.4, F g−1) and neat PA (168 F g−1), respectively. The specific capacitance of PP@SPAC5, PP@SPAC10, PP@SPAC15, PP@SPAC30, PP@SPAC50, and neat PP composites series, are 37.5, 76.4, 202.8, 144, 139.5, and 146 F g−1 respectively, at 1.0 A g−1. The rapid GCD characteristics of PA@SPAC30 and PP@SPAC15 are due to their excellent porosity and well-structured architectural morphology, which facilitate short ion diffusion paths and unrestricted access during GCD cycles. The specific capacitance are remains 94.55 % and 95.8 % of initial capacitance demonstrating that the PA@SPAC30 and PP@SPAC15 electrodes exhibit remarkable cyclability over 5000 GCD cycles.
{"title":"Improved capacitive performance of conducting polymer with incorporation of biomass derived activated carbon for supercapacitors","authors":"Murugan Vinayagam , Rajendran Suresh Babu , Arumugam Sivasamy , A.L.F. de Barros","doi":"10.1016/j.diamond.2025.112165","DOIUrl":"10.1016/j.diamond.2025.112165","url":null,"abstract":"<div><div>Nanocomposites that integrate electrostatic charge accumulation and faradic reaction mechanisms hold significant potential as high-performance supercapacitor electrodes for electrochemical energy storage. However, the development of low-cost carbon composites derived from renewable resources remains challenging. Herein, we demonstrate two different conducting polymers such as polyaniline (PA) and polypyrrole (PP) with incorporation of biomass-derived activated carbon from <em>Strychnos Potatorum</em> shells (SPAC) through in-situ polymerization. The SPAC was prepared through pre‑carbonization followed by a physical activation method. The structural defects of the as-synthesized polymer composites were characterized thoroughly by various physicochemical techniques including Fourier transform infrared (FT-IR), Raman, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and Field emission scanning electron microscopy (FE-SEM). Further, the PA and PP composite electrode materials were examined by electrochemical methods such as cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. Under the optimal conditions, the high specific capacitance was observed in PA@SPAC30 (214 F g<sup>−1</sup>) at 1.0 A g<sup>−1</sup> compared to other composites such as PA@SPAC5 (35.2 F g<sup>−1</sup>), PA@SPAC10 (75.2 F g<sup>−1</sup>), PA@SPAC15 (101.4 F g<sup>−1</sup>), PA@SPAC50 (175.4, F g<sup>−1</sup>) and neat PA (168 F g<sup>−1</sup>), respectively. The specific capacitance of PP@SPAC5, PP@SPAC10, PP@SPAC15, PP@SPAC30, PP@SPAC50, and neat PP composites series, are 37.5, 76.4, 202.8, 144, 139.5, and 146 F g<sup>−1</sup> respectively, at 1.0 A g<sup>−1</sup>. The rapid GCD characteristics of PA@SPAC30 and PP@SPAC15 are due to their excellent porosity and well-structured architectural morphology, which facilitate short ion diffusion paths and unrestricted access during GCD cycles. The specific capacitance are remains 94.55 % and 95.8 % of initial capacitance demonstrating that the PA@SPAC30 and PP@SPAC15 electrodes exhibit remarkable cyclability over 5000 GCD cycles.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112165"},"PeriodicalIF":4.3,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.1016/j.diamond.2025.112146
Abdul Khaliq , Sarah A. Alsalhi , Abhinav Kumar
Transition metal-based spinel oxides have become attractive materials for supercapacitor electrodes because of higher specific capacitance (Cs) and low cost. Nonetheless, spinel materials have limited stability because of small interfacial area. Carbonaceous electrode materials like rGO mitigated this problem by enhancing the electroactive surface area and increasing the active sites. This study employed hydrothermal synthesis to fabricate NiBi2O4/rGO (NBO/rGO). The materials potential as electrodes was evaluated utilizing 3-electrode configuration and several electrochemical techniques to evaluate the attributes of NBO and NBO/rGO. The fabricated NBO/rGO demonstrates Cs of 1104.87 F g−1 at 1 A g−1 also remarkable stability over the 3000th cycle and energy density (25.79 Wh kg−1). Electrochemical studies indicate that rGO enhances the overall stability of NBO by prolonging the discharge time interval, hence boosting the Cs. This study demonstrates that rGO can enhance the performance of NBO in various energy-storing systems.
{"title":"Efficient NiBi2O4/rGO electrode material for energy storage device","authors":"Abdul Khaliq , Sarah A. Alsalhi , Abhinav Kumar","doi":"10.1016/j.diamond.2025.112146","DOIUrl":"10.1016/j.diamond.2025.112146","url":null,"abstract":"<div><div>Transition metal-based spinel oxides have become attractive materials for supercapacitor electrodes because of higher specific capacitance (C<sub>s</sub>) and low cost. Nonetheless, spinel materials have limited stability because of small interfacial area. Carbonaceous electrode materials like rGO mitigated this problem by enhancing the electroactive surface area and increasing the active sites. This study employed hydrothermal synthesis to fabricate NiBi<sub>2</sub>O<sub>4</sub>/rGO (NBO/rGO). The materials potential as electrodes was evaluated utilizing 3-electrode configuration and several electrochemical techniques to evaluate the attributes of NBO and NBO/rGO. The fabricated NBO/rGO demonstrates C<sub>s</sub> of 1104.87 F g<sup>−1</sup> at 1 A g<sup>−1</sup> also remarkable stability over the 3000<sup>th</sup> cycle and energy density (25.79 Wh kg<sup>−1</sup>). Electrochemical studies indicate that rGO enhances the overall stability of NBO by prolonging the discharge time interval, hence boosting the C<sub>s</sub>. This study demonstrates that rGO can enhance the performance of NBO in various energy-storing systems.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112146"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.1016/S0925-9635(25)00231-6
{"title":"Outside Front Cover - Journal name, Cover image, Volume issue details, ISSN, Cover Date, Elsevier Logo and Society Logo if required","authors":"","doi":"10.1016/S0925-9635(25)00231-6","DOIUrl":"10.1016/S0925-9635(25)00231-6","url":null,"abstract":"","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"153 ","pages":"Article 112174"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.1016/j.diamond.2025.112157
Haifa A. Al-Yousef , Lamia Abu El Maati , Muneerah Alomar , Hafiz Muhammad Tahir Farid , Salma Eman , Taghreed Bahlool
Energy is a primary requirement of the modern age, and water-splitting is recognized as a green energy source. Developing efficient, high-performance, and cost-effective electrocatalysts has become a significant pursuit in improving water-splitting productivity. In this context, a hydrothermally synthesized, advantageous, environmentally friendly and economically efficient FeAlO3/g-CN (FAO/g-CN) hybrid material enhances water oxidation. Multiple analytical methods examine the components' morphological, textural, structural, and compositional characteristics, highlighting the need for efficient and cost-effective solutions. The electrochemical characteristics of the FeAlO3/g-CN composite have been evaluated in a 1 M potassium hydroxide (KOH), revealing an extraordinarily lower overpotential (212 mV) at an optimal current density (j) of 10 mA/cm2. A minimum charge transfer resistance (Rct) of 0.04 Ω and notable longevity (50 h) indicates the synthesized material's outstanding prospects for oxygen evolution reaction (OER). Subsequent analysis has exposed a notably low Tafel value (32 mV/dec), signifying that FeAlO3/g-CN nanocomposite has enhanced electrocatalytic effectiveness and rapid reaction kinetics. The nanocomposite demonstrates significant applications for water electrolysis and other electrochemical activities, thereby underlining its potential impact on renewable energy.
{"title":"A novel FeAlO3/g-CN (FAO/g-CN) material as an electrocatalyst with promising potential for OER","authors":"Haifa A. Al-Yousef , Lamia Abu El Maati , Muneerah Alomar , Hafiz Muhammad Tahir Farid , Salma Eman , Taghreed Bahlool","doi":"10.1016/j.diamond.2025.112157","DOIUrl":"10.1016/j.diamond.2025.112157","url":null,"abstract":"<div><div>Energy is a primary requirement of the modern age, and water-splitting is recognized as a green energy source. Developing efficient, high-performance, and cost-effective electrocatalysts has become a significant pursuit in improving water-splitting productivity. In this context, a hydrothermally synthesized, advantageous, environmentally friendly and economically efficient FeAlO<sub>3</sub>/g-CN (FAO/g-CN) hybrid material enhances water oxidation. Multiple analytical methods examine the components' morphological, textural, structural, and compositional characteristics, highlighting the need for efficient and cost-effective solutions. The electrochemical characteristics of the FeAlO<sub>3</sub>/g-CN composite have been evaluated in a 1 M potassium hydroxide (KOH), revealing an extraordinarily lower overpotential (212 mV) at an optimal current density (j) of 10 mA/cm<sup>2</sup>. A minimum charge transfer resistance (R<sub>ct</sub>) of 0.04 Ω and notable longevity (50 h) indicates the synthesized material's outstanding prospects for oxygen evolution reaction (OER). Subsequent analysis has exposed a notably low Tafel value (32 mV/dec), signifying that FeAlO<sub>3</sub>/g-CN nanocomposite has enhanced electrocatalytic effectiveness and rapid reaction kinetics. The nanocomposite demonstrates significant applications for water electrolysis and other electrochemical activities, thereby underlining its potential impact on renewable energy.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112157"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.diamond.2025.112164
Ondrej Szabó, Gabriel Vanko, Kateřina Aubrechtová Dragounová, Štěpán Potocký, Alexander Kromka
This study investigates the deep etching characteristics of microcrystalline diamond films using a Ni-catalyzed thermochemical process conducted at different temperatures (750–975 °C) and gas compositions. Under H2 microwave plasma conditions, minimal etching was observed beneath the Ni mask. Although introducing CO₂ into the gas mixture enhanced the etching rate by factors of 2–3, it resulted in non-selective etching of unmasked regions.
Changing to water vapor conditions led to superior etching selectivity, though the process was still pressure-dependent. At low pressure (65 mbar), catalytic etching achieved a maximum depth of 5–6 μm due to saturated graphitization around Ni. This limitation was overcome by increasing atmospheric pressure, enabling the formation of depth structures up to 20 μm with an etching rate of 45 μm/h. Temperature-dependent studies were conducted to evaluate the etch profile evolution. Using a 200 nm thick Ni mask at 900 °C under atmospheric pressure conditions, we achieved highly anisotropic etching with vertical sidewalls, contrasting with the sloped profiles typically observed in single-crystal diamond etching. This technology presents a cost-effective alternative to conventional dry plasma etching processes for fabricating complex 3D structures.
{"title":"Thermochemical etching of polycrystalline diamond films by nickel","authors":"Ondrej Szabó, Gabriel Vanko, Kateřina Aubrechtová Dragounová, Štěpán Potocký, Alexander Kromka","doi":"10.1016/j.diamond.2025.112164","DOIUrl":"10.1016/j.diamond.2025.112164","url":null,"abstract":"<div><div>This study investigates the deep etching characteristics of microcrystalline diamond films using a Ni-catalyzed thermochemical process conducted at different temperatures (750–975 °C) and gas compositions. Under H<sub>2</sub> microwave plasma conditions, minimal etching was observed beneath the Ni mask. Although introducing CO₂ into the gas mixture enhanced the etching rate by factors of 2–3, it resulted in non-selective etching of unmasked regions.</div><div>Changing to water vapor conditions led to superior etching selectivity, though the process was still pressure-dependent. At low pressure (65 mbar), catalytic etching achieved a maximum depth of 5–6 μm due to saturated graphitization around Ni. This limitation was overcome by increasing atmospheric pressure, enabling the formation of depth structures up to 20 μm with an etching rate of 45 μm/h. Temperature-dependent studies were conducted to evaluate the etch profile evolution. Using a 200 nm thick Ni mask at 900 °C under atmospheric pressure conditions, we achieved highly anisotropic etching with vertical sidewalls, contrasting with the sloped profiles typically observed in single-crystal diamond etching. This technology presents a cost-effective alternative to conventional dry plasma etching processes for fabricating complex 3D structures.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112164"},"PeriodicalIF":4.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-28DOI: 10.1016/j.diamond.2025.112160
Santhosh Kumar Kamarapu , M. Amarnath , Saurabh Tiwari
The performance of roller bearings is often compromised by the excessive temperature rise and wear, which encourages the author to search for a more effective lubrication solution. This study examines the heat transfer capability of a bio-based nanolubricant blend to improve heat transfer and reduce wear in roller-bearing fatigue load conditions. In this study, Elaeis guineensis and mineral oil blend used in addition to functionalized multiwall carbon nanotubes. The lubricant's thermo-rheological results were evaluated over 1000 h of operation using NJ307 cylindrical roller bearings. The study quantified the lubricants rheological behaviour, film thickness, classification of wear debris, and changes in temperature with the proposed nanolubricant blend and compared the results with commercial grade lubricant. The findings indicated that the nanolubricant attained a temperature reduction of up to 37 % compared to traditional mineral oil. A significant surface wear reduction observed in nanolubricated bearing due to stable enhanced nanolubrication film developed between steel-steel contact surfaces. This experimental study provides substantial insights into nanomaterial-enhanced bio-lubricants, which demonstrate improved sustainability and performance in industrial bearing systems, hence promoting their potential commercial application.
{"title":"Nanoenhanced biolubricant for improving lubrication in roller bearing steel-steel contact surfaces - a comparative tribological study","authors":"Santhosh Kumar Kamarapu , M. Amarnath , Saurabh Tiwari","doi":"10.1016/j.diamond.2025.112160","DOIUrl":"10.1016/j.diamond.2025.112160","url":null,"abstract":"<div><div>The performance of roller bearings is often compromised by the excessive temperature rise and wear, which encourages the author to search for a more effective lubrication solution. This study examines the heat transfer capability of a bio-based nanolubricant blend to improve heat transfer and reduce wear in roller-bearing fatigue load conditions. In this study, <em>Elaeis guineensis</em> and mineral oil blend used in addition to functionalized multiwall carbon nanotubes. The lubricant's thermo-rheological results were evaluated over 1000 h of operation using NJ307 cylindrical roller bearings. The study quantified the lubricants rheological behaviour, film thickness, classification of wear debris, and changes in temperature with the proposed nanolubricant blend and compared the results with commercial grade lubricant. The findings indicated that the nanolubricant attained a temperature reduction of up to 37 % compared to traditional mineral oil. A significant surface wear reduction observed in nanolubricated bearing due to stable enhanced nanolubrication film developed between steel-steel contact surfaces. This experimental study provides substantial insights into nanomaterial-enhanced bio-lubricants, which demonstrate improved sustainability and performance in industrial bearing systems, hence promoting their potential commercial application.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112160"},"PeriodicalIF":4.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the temporal evolution of growing single-crystal diamond surfaces is microscopically observed during microwave plasma-enhanced chemical vapor deposition using an in-situ observation system equipped with a long-distance microscope. Growth on substrates with small off-axis angles from the (001) plane effectively induced a unidirectional lateral flow of surface structures. Introducing a small amount of nitrogen into the gas phase resulted in the formation of striped patterns owing to the macroscopic riser/terrace structures on the surface. At a relatively small off-axis angle of 2.7°, the surface remained relatively smooth over a growth period exceeding 15 h. The addition of nitrogen suppressed step motion and significantly reduced the lateral flow rate relative to the vertical growth rate. Raman spectroscopy revealed that a lower lateral-to-vertical growth rate ratio correlated with higher nitrogen concentrations in the grown diamond film, as indicated by the relative luminescence intensity of nitrogen vacancy centers. This study demonstrates a technique for monitoring and controlling surface morphology and, potentially, the physical properties of growing diamond films, contributing to advancements in diamond research and industrial applications.
{"title":"In-situ microscopic observation of single-crystal diamond during chemical vapor deposition","authors":"Kaishu Nitta, Takehiro Shimaoka, Hideaki Yamada, Nobuteru Tsubouchi, Akiyoshi Chayahara, Yoshiaki Mokuno","doi":"10.1016/j.diamond.2025.112154","DOIUrl":"10.1016/j.diamond.2025.112154","url":null,"abstract":"<div><div>In this study, the temporal evolution of growing single-crystal diamond surfaces is microscopically observed during microwave plasma-enhanced chemical vapor deposition using an <em>in-situ</em> observation system equipped with a long-distance microscope. Growth on substrates with small off-axis angles from the (001) plane effectively induced a unidirectional lateral flow of surface structures. Introducing a small amount of nitrogen into the gas phase resulted in the formation of striped patterns owing to the macroscopic riser/terrace structures on the surface. At a relatively small off-axis angle of 2.7°, the surface remained relatively smooth over a growth period exceeding 15 h. The addition of nitrogen suppressed step motion and significantly reduced the lateral flow rate relative to the vertical growth rate. Raman spectroscopy revealed that a lower lateral-to-vertical growth rate ratio correlated with higher nitrogen concentrations in the grown diamond film, as indicated by the relative luminescence intensity of nitrogen vacancy centers. This study demonstrates a technique for monitoring and controlling surface morphology and, potentially, the physical properties of growing diamond films, contributing to advancements in diamond research and industrial applications.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112154"},"PeriodicalIF":4.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143563363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-27DOI: 10.1016/j.diamond.2025.112147
Ekpenyong O. Okon , Gideon E. Mathias , Musa Runde , Mohammed Yaqob , Ahmed Adnan AL-Khafagi
Here, a fullerene-based (C60) material comprising sixty carbon atoms was selected due to its advantageous properties including sensitivity, electrical conductivity, and having a structure that can be readily modified. The C60 bare surface was further doped with Ti, a metal, and then decorated with Cu to improve its overall properties and enhance its adsorption of NO2, NO, CO2, CO, and SO2 gasses using the density function theory (DFT) computation conducted at the PBE0/LanL2DZ level of theory. The surface Cu-Ti@C60 was studied at the O, N, and C sites to determine the sites exhibiting the highest adsorption strength for the studied gases. The NO₂-N-Cu-Ti@C60 complex possessed the most significant adsorption energy of −14.3571 eV while the CO2 binding at the O-site exhibited the lowest adsorption energy of −0.58638 eV. This indicates that the Cu-Ti@C60 surface binds greatly to the NO2 and NO gases with a good adsorption strength observed for SO2 gas. Also, there was a minimal change in the energy gap of the surface after adsorption with studied gases which showcased the stability of the systems. These analyses carried out in this study position Cu-Ti@C60 surface to be a promising material in developing a sensor device for NO2, NO, CO2, CO, and SO2 with a strong adsorption rate for NO2, NO, SO2, CO, CO2 in a descending sequence.
{"title":"Titanium and copper tailoring of fullerene (Cu-Ti@C60) as a sensor nanostructured for toxic gas pollutants: A DFT study","authors":"Ekpenyong O. Okon , Gideon E. Mathias , Musa Runde , Mohammed Yaqob , Ahmed Adnan AL-Khafagi","doi":"10.1016/j.diamond.2025.112147","DOIUrl":"10.1016/j.diamond.2025.112147","url":null,"abstract":"<div><div>Here, a fullerene-based (C<sub>60</sub>) material comprising sixty carbon atoms was selected due to its advantageous properties including sensitivity, electrical conductivity, and having a structure that can be readily modified. The C<sub>60</sub> bare surface was further doped with Ti, a metal, and then decorated with Cu to improve its overall properties and enhance its adsorption of NO<sub>2</sub>, NO, CO<sub>2</sub>, CO, and SO<sub>2</sub> gasses using the density function theory (DFT) computation conducted at the PBE0/LanL2DZ level of theory. The surface Cu-Ti@C<sub>60</sub> was studied at the O, N, and C sites to determine the sites exhibiting the highest adsorption strength for the studied gases. The NO₂-N-Cu-Ti@C<sub>60</sub> complex possessed the most significant adsorption energy of −14.3571 eV while the CO<sub>2</sub> binding at the O-site exhibited the lowest adsorption energy of −0.58638 eV. This indicates that the Cu-Ti@C<sub>60</sub> surface binds greatly to the NO<sub>2</sub> and NO gases with a good adsorption strength observed for SO<sub>2</sub> gas. Also, there was a minimal change in the energy gap of the surface after adsorption with studied gases which showcased the stability of the systems. These analyses carried out in this study position Cu-Ti@C<sub>60</sub> surface to be a promising material in developing a sensor device for NO<sub>2</sub>, NO, CO<sub>2</sub>, CO, and SO<sub>2</sub> with a strong adsorption rate for NO<sub>2</sub>, NO, SO<sub>2</sub>, CO, CO<sub>2</sub> in a descending sequence.</div></div>","PeriodicalId":11266,"journal":{"name":"Diamond and Related Materials","volume":"154 ","pages":"Article 112147"},"PeriodicalIF":4.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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