Synthetic routes to manganese oxoborate and correlations between experimental parameters and properties

Manganese Oxoborate‐Based Nanostructures as Novel Oxygen Evolution Catalysts in Neutral Media

“…As demonstrated in our previous research, [16] the manganese oxoborate samples synthesized by solution combustion, solid‐state, and hydrothermal methods all gave the same powder XRD patterns (Figure 1). No major differences between the patterns and no impurity phases were observed though different synthesis strategies were employed.…”

“…The catalysts displayed a descending electrochemical activity in the order of QS>IR>NR, verifying the fundamental role of the morphology of the thin film layer on the FTO surface in nano‐sized spherical, irregular or rod forms. The electrode prepared with QS‐Mn 2 OBO 3 showed the best performance due to the higher surface area of the spherical particles concerning the others [16] . Although the NR‐Mn 2 OBO 3 exhibited a lower performance, the onset potential and the overpotential values required to reach 1 mA cm −2 current density are competitive compared to the other catalysts (Table 2).…”

“…The highest initial electrochemical activity was recorded for the QS‐catalyst. Since the surface area of the QS‐Mn 2 OBO 3 is the highest (9.60 m 2 /g) [16] and QS morphology allows dense and uniform packing over the FTO surface, O 2 gas bubbles regularly grow and dissipate from the electrode surface. However, the growth of O 2 gas bubbles on the electrode surface limits the circulation of the electrolyte and prevents sustainable gas release from the electrode surface.…”

“…The dense layer structure of spherical and irregular particles restricts electrolyte circulation. The NR‐catalyst, on the other hand, showed the lowest initial activity due to smaller surface area (4.60 m 2 /g) (Table S1) [16] and irregular stacking of nanorods, however, a greater stability in long term tests. The stacking of nanorods forms a 3‐dimensional (3D) porous structure by creating cavities on the FTO surface.…”

“…Carbon‐based composite materials have great potential for OER reactions due to their high surface area, catalytically active sites, and stability [15] . We have recently reported the synthesis and characterization of QS (quasi‐spherical), IR (irregular), and NR (nanorod) Mn 2 OBO 3 [16] . Herein, we present the OER performances of XC‐72 Carbon‐supported QS‐, IR‐ and NR‐Mn 2 OBO 3 composite catalysts at neutral medium.…”