Zabielaite Ausrine, Balciunaite Aldona, Upskuviene Daina, Simkunaite Dijana, Levinas Ramunas, Niaura Gediminas, Vaiciuniene Jurate, Jasulaitiene Vitalija, Tamasauskaite-Tamasiunaite Loreta, Norkus Eugenijus
Center for Physical Sciences and Technology (FTMC), LT-10257 Vilnius, Lithuania.
Materials (Basel). 2023 Aug 30;16(17):5923. doi: 10.3390/ma16175923.
This study focuses on fabricating cobalt particles deposited on graphitic carbon nitride (Co/gCN) using annealing, microwave-assisted and hydrothermal syntheses, and their employment in hydrogen and oxygen evolution (HER and OER) reactions. Composition, surface morphology, and structure were examined using inductively coupled plasma optical emission spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The performance of Co-modified gCN composites for the HER and OER were investigated in an alkaline media (1 M KOH). Compared to the metal-free gCN, the modification of gCN with Co enhances the electrocatalytic activity towards the HER and OER. Additionally, thermal annealing of both Co(NO) and melamine at 520 °C for 4 h results in the preparation of an effective bifunctional CoO/gCN catalyst for the HER with the lower of -0.24 V, a small overpotential of -294.1 mV at 10 mA cm, and a low Tafel slope of -29.6 mV dec in a 1.0 M KOH solution and for the OER with the onset overpotential of 286.2 mV and overpotential of 422.3 mV to achieve a current density of 10 mA cm with the Tafel slope of 72.8 mV dec.
本研究着重于通过退火、微波辅助和水热合成法制备沉积在石墨相氮化碳上的钴颗粒（Co/gCN），以及它们在析氢和析氧反应（HER和OER）中的应用。使用电感耦合等离子体发射光谱、X射线光电子能谱和X射线衍射对其组成、表面形态和结构进行了研究。在碱性介质（1 M KOH）中研究了Co改性gCN复合材料的HER和OER性能。与无金属的gCN相比，用Co对gCN进行改性可增强其对HER和OER的电催化活性。此外，将Co(NO)和三聚氰胺在520℃下热退火4小时，可制备出一种有效的双功能CoO/gCN催化剂用于HER，在1.0 M KOH溶液中，其起始过电位为-0.24 V，在10 mA cm时的过电位为-294.1 mV，塔菲尔斜率为-29.6 mV dec；用于OER时，起始过电位为286.2 mV，过电位为422.3 mV以达到10 mA cm的电流密度，塔菲尔斜率为72.8 mV dec。
