Ln3+(Eu3+/Tb3+)-hybridized fluorescent sands with smart self-cleaning property for outdoor photonic indicators (OPIs)

•The hybrid fluorescent sands with excellent optical and outstanding self-cleaning properties are proposed.•Fluorescent sands were applied for the outdoor photonic indicators (OIPs) with high color purity and strong emissions.•The fluorescent sands exhibited excellent self-cleaning properties with the contact angle 160º and the rolling angle ﹤10º.•The self-cleaning property of hybrid fluorescent sands prevent the OPIs from contaminating by the rain, ice and dust.