| The global dearth of fossil energy and the destruction of the environment caused by its burning are both major contributors to the energy crisis.In recent years,obtaining hydrogen from photocatalytic reaction of semiconductor has developed rapidly,which is expected to become a crucial method of hydrogen evolution in the future.As one of the most widely researched semiconductor materials in the field of photocatalytic research.Hypotoxicity,low raw material price and high stability of Ti O2 has catched eye of researchers.Among several different crystal structure of Ti O2,the two-dimensional nanosheet structure of Ti O2（B）owns potential of modification.Large specific surface area and short carrier migration distance,which make it have a enormous adhibition potency in the flied of photocatalytic hydrogen evolution.Among the several modification methods of semiconductor photocatalysis,the exfoliation of two-dimensional nanosheets is a special method which enable the carrier quickly migrate to the surface,thus improving its photocatalytic activity.Supported co-catalyst is also a common modification method.Some non-noble metal nanoparticles have excellent electrical conductivity and low overpotential.The appropriate method to anchor non-noble metal onto the catalyst surface can effectively improve its photocatalytic activity which is expected to replace the precious metal cocatalyst such as Pt,thus reducing the cost of photocatalysis.In this paper,we explored the exfoliating conditions of Ti O2（B）nanosheets,the loading of non-noble metal nanoparticles and discussed the photocatalytic hydrogen production performance and mechanism before and after modification.The main research contents are as follows:（1）Ti O2（B）nanosheets were synthesised by a simple solvothermal route which using ethylene glycol,deionized water and titanium trichloride as raw materials.The Ti O2（B）nanosheets were exfoliated by ion intercalation method.Meanwhile,we discussed the effects of different solvents and different kinds of acetate on the exfoliating conditions.The morphology and structure of Ti O2（B）and exfoliated Ti O2（B）were analyzed by TEM,BET and other characterization methods.The specific surface area of Ti O2（B）nanosheets was effectively improved by 34%.We tested the photocatalytic hydrogen production performance of the Ti O2（B）nanosheets which loaded Pt as the co-catalyst.The hydrogen production rate of the material under optimal exfoliating conditions reached 11.6 mmol·g-1·h-1 which was 14.5 times higher than that of the unexfoliated material.Subsequently,we verified the enhancement of the photocatalytic activity of the Ti O2（B）nanosheets by a series of photochemical characterization.Finally,we discussed the mechanism of photocatalytic hydrogen production.（2）Taking Ti O2（B）nanosheets under optimal exfoliating conditions as the base,we added non-noble metal acetate in the oil bath process of exfoliating so that non-noble metal ions were evenly dispersed to the surface of the material.Then Na BH4 was used as the reducing agent to reduce the non-precious metal ions on the nanosheets in-situ.Ti O2（B）supported by Ni atoms reached the highest hydrogen production rate of 6.3 mmol·g-1·h-1which was 21 times higher than that of unexfoliated Ti O2（B）.Ti O2（B）supported by Cu atoms reached the highest hydrogen production rate of 4.9 mmol·g-1·h-1,which was 16.9times higher than that of unexfoliated Ti O2（B）.Eventually,we achieved a battery of photochemical tests to proved the effective improvement of photocatalytic performance. |
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