If it is for a job for with you work as an "employee" receiving a W-2, and they are not reimbursed to you, then you can deduct them as an Unreimbursed Employee Business Form 2106. It goes on Schedule A Itemized Deductions in the Misc section subject to a 2% of Adjusted Gross Income threshold. If you itemize deductions (as opposed to the Standard Deduction) , and your expenses are high enough, it may benefit you.
Where do I enter job-related employee expenses? (Form 2106)
How does the itemized deduction differ from the standard deduction?
What's my standard deduction?