Lifeless means something without life, a corpse could be described as being lifeless, we also say a lifeless body; dolls are said to have lifeless eyes although the eyes appear realistic they are expressionless and blank. If you describe a group of photos as being lifeless the viewer might interpret this two ways. First, as a metaphor, the subjects are indeed without life, they are non-living things whose existence have been recorded in light (photo). Secondly, and possibly the one you most want to avoid, the photos are dull, expressionless and dead-looking.
Still life is probably the term you are looking for. Wikipedia describes it as
Still life is a work of art depicting mostly inanimate subject matter,
typically commonplace objects which may be either natural (food,
flowers, dead animals, plants, rocks, or shells) or man-made (drinking
glasses, books, vases, jewelry, coins, pipes, and so on).
Still life Photography
Still life photography is the depiction of inanimate subject matter,
most typically a small grouping of objects. Still life photography,
more so than other types of photography, such as landscape or
portraiture, gives the photographer more leeway in the arrangement of
design elements within a composition.
Still life photography is a demanding art, one in which the
photographers are expected to be able to form their work with a
refined sense of lighting, coupled with compositional skills. The
still life photographer makes pictures rather than takes them. Knowing
where to look for propping and surfaces also is a required skill.
As alternative titles to still life consider man-made "life"; post-industrial; or the gloomier dystopia.