Scientific Achievement
2D MoS2 nanosheets with mixed phases and interfaces were synthesized and tailored as photocatalysts with 400% more efficient solar hydrogen production from water splitting than a single phase alone.
Significance and Impact
Development of efficient and inexpensive photocatalysts that don’t involve noble metals is crucial for practical harvesting solar energy into fuels.
Research Details
– A chemical exfoliation and annealing method was developed to produce single layer MoS2 crystals with mixed phases.
– The content of each phase (2H,1T, 1T‘) of MoS2 was precisely tuned by varying the annealing temperature, from as-synthesized 2H-1T, to 2H-1T‘ after a 60°C treatment, to mostly 2H after higher temperature treatments.
– DFT calculations correlated the 2H/1T‘ junctions and the basal sites of the 1T’ phase as the sites for the efficient separation of photogenerated charge and hydrogen evolution, respectively.
R. Peng, L. Liang, Z. D. Hood, A. Boulesbaa, A. Puretzky, A. V. Ievlev, J. Come, O. S. Ovchinnikova, H. Wang, C. Ma, M. Chi, B. G. Sumpter, Z. Wu. ACS Catalysis 6, 6723-6729 (2016). DOI: 10.1021/acscatal.6b02076
