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Supplemental material, sj-docx-1-tej-10.1177_20417314221116754 for Therapeutic potential of epiphyseal growth plate cells for bone regeneration in an osteoporosis model by Inho Baek, Alvin Bacero Bello, Jieun Jeon, Yoshie Arai, Byung-Hyun Cha, Byoung Ju Kim and Soo-Hong Lee in Journal of Tissue Engineering

Supplemental material, sj-docx-1-tej-10.1177_20417314221116754 for Therapeutic potential of epiphyseal growth plate cells for bone regeneration in an osteoporosis model by Inho Baek, Alvin Bacero Bello, Jieun Jeon, Yoshie Arai, Byung-Hyun Cha, Byoung Ju Kim and Soo-Hong Lee in Journal of Tissue Engineering

The electrochemical CO2 reduction reaction (CO2RR) using Cu-based catalysts holds great potential for producing valuable multi-carbon products from renewable energy. However, the chemical and structural state of Cu catalyst surfaces during the CO2RR remains a matter of debate. Here, we show the structural evolution of the near-surface region of polycrystalline Cu electrodes under in situ conditions through a combination of grazing incidence X-ray absorption spectroscopy (GIXAS) and X-ray diffraction (GIXRD). The in situ GIXAS reveals that the surface oxide layer is fully reduced to metallic Cu before the onset potential for CO2RR, and the catalyst maintains the metallic state across the potentials relevant to the CO2RR. We also find a preferential surface reconstruction of the polycrystalline Cu surface toward (100) facets in the presence of CO2. Quantitative analysis of the reconstruction profiles reveals that the degree of reconstruction increases with increasingly negative applied potentials, and it persists when the applied potential returns to more positive values. These findings show that the surface of Cu electrocatalysts is dynamic during the CO2RR, and emphasize the importance of in situ characterization to understand the surface structure and its role in electrocatalysis.

The effect of porous structures on the electrocatalytic activity of N-doped carbon is studied by using electrochemical analysis techniques and the result is applied to synthesize highly active and stable Fe-N-C catalyst for oxygen reduction reaction (ORR). We developed synthetic procedures to prepare three types of N-doped carbon model catalysts that are designed for systematic comparison of the porous structures. The difference in their catalytic activity is investigated in relation to the surface area and the electrochemical parameters. We found that macro- and mesoporous structures contribute to different stages of the reaction kinetics. The catalytic activity is further enhanced by loading the optimized amount of Fe to prepare Fe-N-C catalyst. In both N-doped carbon and Fe-N-C catalysts, the hierarchical porous structure improved electrocatalytic performance in acidic and alkaline media. The optimized catalyst exhibits one of the best ORR performance in alkaline medium with excellent long-term stability in anion exchange membrane fuel cell and accelerated durability test. Our study establishes a basis for rationale design of the porous carbon structure for electrocatalytic applications.

Tri-crystalline silicon wafers have three different orientations and three-grain boundaries. In this paper, tri-crystalline silicon (tri-Si) wafers have been used for the fabrication of buried contact solar cells. The optical and micro-structural properties of these cells after texturing in KOH solution have been investigated and compared with those of cast mult- crystalline silicon (multi-Si) wafers. We employed a cost effective fabrication process and achieved buried contact solar cell (BCSC) energy conversion efficiencies up to whereas the cast multi-Si wafer has efficiency around .