Simple synthesis of hollow-wagon-wheel sorbent (with CA/CTAB sacrificed template). • High surface-area microporous hollow spheres of silica@Mo(VI) for As(V) sorption. • Pseudo-first order rate and Sips equations for modeling kinetics and isotherms. • Used as naked-eye sensor, the material detects As(V) at level as low as 0.3 µM. • Efficient As(V) desorption using 1 mM NaOH solution and high recycling performance.