Synthesis of Sulfur@g-C3N4 and CuS@g-C3N4 Catalysts for Hydrogen Production from Sodium Borohydride

In this work, the S@g-C3N4 and CuS@g-C3N4 catalysts were prepared via the polycondensation process. The structural properties of these samples were completed on XRD, FTIR and ESEM techniques. The XRD pattern of S@g-C3N4 presents a sharp peak at 27.2 & DEG; and a weak peak at 13.01 & DEG; and the reflections of CuS belong to the hexagonal phase. The interplanar distance decreased from 0.328 to 0.319 nm that facilitate charge carrier separation and promoting H-2 generation. FTIR data revealed the structural change according to absorption bands of g-C3N4. ESEM images of S@g-C3N4 exhibited the described layered sheet structure for g-C3N4 materials and CuS@g-C3N4 demonstrated that the sheet materials were fragmented throughout the growth process. The data of BET revealed a higher surface area (55 m(2)/g) for the CuS-g-C3N4 nanosheet. The UV-vis absorption spectrum of S@g-C3N4 showed a strong peak at 322 nm, which weakened after the growth of CuS at g-C3N4. The PL emission data showed a peak at 441 nm, which correlated with electron-hole pair recombination. The data of hydrogen evolution showed improved performance for the CuS@g-C3N4 catalyst (5227 mL/g & BULL;min). Moreover, the activation energy was determined for S@g-C3N4 and CuS@g-C3N4, which showed a lowering from 47.33 & PLUSMN; 0.02 to 41.15 & PLUSMN; 0.02 KJ/mol.

Automated summary

The S@g-C3N4 and CuS@g-C3N4 catalysts were prepared using the polycondensation process and characterized using XRD, FTIR, and ESEM techniques. The S@g-C3N4 sample showed sharp and weak peaks at 27.2° and 13.01°, respectively, while the CuS reflections indicated a hexagonal phase. The interplanar distance decreased, promoting charge carrier separation and H-2 generation. FTIR data revealed structural changes in g-C3N4, and ESEM images showed a layered sheet structure for S@g-C3N4 and fragmented sheets for CuS@g-C3N4. BET data indicated a higher surface area in CuS-g-C3N4 nanosheets. UV-vis absorption and PL emission spectra showed changes after CuS growth on g-C3N4. The CuS@g-C3N4 catalyst exhibited improved hydrogen evolution performance and a lower activation energy than S@g-C3N4.