Living systems use catalysis to achieve chemical transformations to comply with their
needs in terms of energy and building blocks. The pH is a powerful means to regulate such processes,
which also influences synthetic systems. In fact, the pH sensitivity of artificial photocatalysts, such
as bismuth vanadate, bears the strong potential of flexibly influencing both the motion pattern and
the speed of catalytic microswimmers, but it has rarely been investigated to date. In this work, we
first present a comprehensive view of the motion behavior of differently shaped bismuth vanadate
microswimmers, discuss influences, such as shape, pH, and conductivity of the solutions, and find
that the motion pattern of the swimmers switches between upright and horizontal at their point of
zero charge. We then apply an immobilizable hydroxypyrene derivative to our substrates to locally
influence the pH of the solution by excited-state proton transfer. We find that the motion pattern
of our swimmers is strongly influenced by this functionalization and a third motion mode, called
tumbling, is introduced. Taking other effects, such as an increased surface roughness of the modified
substrates, into account, we critically discuss possible future developments