1. General Information
- **Data Set Title**: Enhanced Water Splitting Performance of Transition Metal Nitrides via Carbon-Based Nanomaterial Integration
- **Authors**:
-Principal investigator and contact person: Anna Ilnicka, Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100 Torun, Poland, e-mail: ailnicka@umk.pl
-Investigator: Laura Kubinska, Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100 Torun, Poland, e-mail: 307382@stud.umk.pl
-Investigator: Mariusz Szkoda, Faculty of Chemistry, Department of Chemistry and Technology of Functional Materials, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland, Advanced Materials Center, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland, e-mail: mariusz.szkoda@pg.edu.pl
-Investigator: Marta Gajewska, Academic Centre for Materials and Nanotechnology, AGH University of Krakow, Mickiewicza 30, 30-059 Kraków, Poland, e-mail: marta.gajewska@agh.edu.pl
-Investigator: Patrycja Grabowska, Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100 Torun, Poland, e-mail: pgrabowska@doktorant.umk.pl
-Investigator: Małgorzata Skorupska, Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100 Torun, Poland, e-mail: gosiaskorupska94@gmail.com
- **Date of data collection**: 2025 year
- **Place of data collection**: Torun, Krakow
- **Keywords***: transition metal nitrides, nitrogen-doped carbon, hydrogen evolution reaction, oxygen evolution reaction
Data language**: English
- **Sources of funding**: National Science Center (NCN) OPUS UMO-2024/53/B/ST5/02770
2. Overview of data and files
- **Folders List**:
1. Raman spectra - containing Raman spectra recorded using a Renishaw InVia Raman spectrometer equipped with a 532 nm excitation laser operating at a power of 2 mW. Folder contain raw data files in .dpt format.
2. High‑resolution transmission electron microscopy (HRTEM) images - containing high‑resolution transmission electron microscopy images recorded using a FEI Tecnai TF20 X‑TWIN microscope equipped with a field‑emission gun (FEG). The microscope was operated at an accelerating voltage of 200 kV. Folder contains raw data files in .tiff format.
3. Energy dispersive spectroscopy (EDS) spectra - containing EDS spectra recorded using a FEI Tecnai TF20 X‑TWIN microscope equipped with a field‑emission gun (FEG). The microscope was operated at an accelerating voltage of 200 kV. The elemental distribution was determined using energy‑dispersive spectroscopy (EDS). Folder contains raw data files in .txt format.
4. X-Ray diffractograms - containing analysis X-ray diffractograms recorded using a Philips X’Pert diffractometer equipped with an X’Celerator Scientific detector. The scans were recorded over a 2θ range of 10°–110°, with a step size of 0.02° and a counting time of 0.48 s per step, using Cu Kα radiation (λ = 1.5406 Å) at 40 kV and 30 mA. Folder contains raw data files in .xy format.
5. Chronoamperograms - were recorded using the potentiostat–galwanostat system of a BioLogic VSP electrochemical workstation under EC-Lab V11.43 software control. The synthesized catalysts were evaluated using a three-electrode system where catalysts were used as the working electrode, a platinum mesh as a counter electrode, and Ag/AgCl (3.0 M KCl) as the reference electrode. To fabricate the electrochemical testing electrode, the mixture of 3 mg catalyst, 750 µL of distilled water, 200 µL of isopropyl alcohol, and 50 µL of 5 wt% Nafion solution was sonicated for 30 min to obtain an ink. Finally, 2.8 µL of the fresh catalyst ink was dropped onto a glassy carbon electrode (2 mm) and dried at room temperature with a loading 0.268 mg cm⁻2. Tests were conducted at a constant current density of 10 mA cm⁻2 for 24 h in 1.0 M KOH aqueous electrolyte. Folder contains raw data files in .txt format.
6. Linear sweep voltammograms - were recorded using the potentiostat–galwanostat system of a BioLogic VSP electrochemical workstation under EC-Lab V11.43 software control. The synthesized catalysts were evaluated using a three-electrode system where catalysts were used as the working electrode, a platinum mesh as a counter electrode, and Ag/AgCl (3.0 M KCl) as the reference electrode. To fabricate the electrochemical testing electrode, the mixture of 3 mg catalyst, 750 µL of distilled water, 200 µL of isopropyl alcohol, and 50 µL of 5 wt% Nafion solution was sonicated for 30 min to obtain an ink. Finally, 2.8 µL of the fresh catalyst ink was dropped onto a glassy carbon electrode (2 mm) and dried at room temperature with a loading 0.268 mg cm⁻2. Voltammograms were recorded for HER and OER at scan rates of 5 mV s⁻1 in 1.0 M KOH aqueous electrolyte. Folder contains raw data files in .txt format.
- **Sample Name List**:
- CoN_Ni: the catalyst was synthesized using Ni(NO₃)₂•6H₂O (0.29 g), Co(NO₃)₂•6H₂O (0.58 g), NH₄F (0.19 g), and urea (0.60 g) in a molar ratio of 1:2:5:10. These reagents were dissolved in 60 mL of distilled water and stirred for 15 minutes using a magnetic stirrer. The resulting solution was then subjected to hydrothermal treatment at 120 °C for 12 hours. After the reaction, the product was collected, washed with distilled water, and dried at 60 °C overnight. The obtained material was subsequently heat-treated in an inert nitrogen (N₂) atmosphere at 700 °C with a heating rate of 4 °C/min. Once the target temperature was reached, the sample was annealed for 2 hours.
- C: carbon was prepared by homogenizing 5 g of lysine, 11 g of K₂CO₃, and 5 g of methylcellulose in 100 mL of distilled water. The mixture was then dried at 100 °C until the water evaporated completely, and the resulting gel was transferred to a porcelain boat. The obtained material was subjected to heat treatment in an inert nitrogen (N₂) atmosphere at 800 °C with a heating rate of 10 °C/min. Once the target temperature was reached, the sample was maintained this way for 1 hour. After carbonization, the resulting mass was etched with concentrated hydrochloric acid using 12 mL of acid per 1 g of sample, followed by thorough washing on a Büchner funnel with distilled water until a neutral pH of the filtrate was achieved.
- CoN_Ni_C(X): To obtain the CoN_Ni_C(X) composite material, Ni(NO₃)₂•6H₂O (0.29 g), Co(NO₃)₂•6H₂O (0.58 g), NH₄F (0.19 g), and urea (0.60 g) were used in a molar ratio of 1:2:5:10. Carbon material (C) was added in an amount corresponding to a specific weight percentage relative to the total mass of all reagents used in the synthesis of the CoN_Ni catalyst. 60 mL of deionized water was added to the reaction mixture, which was then stirred for 15 minutes using a magnetic stirrer. The next step consisted of a hydrothermal treatment carried out at 120 °C for 12 hours. After completion, the product was washed with deionized water and dried overnight at 60 °C. The resulting solid was subjected to further heat treatment under a nitrogen (N₂) atmosphere at 700 °C, with a heating rate of 4 °C/min. Once the target temperature was reached, the sample was annealed for 2 hours. When the carbon material (C) was added to the CoN_Ni catalyst, the resulting sample was designated as CoN_Ni_C(X), where (X) indicates the weight percentage of the carbon material relative to the total mass of reagents used in the catalyst synthesis - 10, 20 and 30.
3. Sharing and access information
- **Licenses/Restrictions**: CC BY - Creative Commons Attribution 4.0.
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